PEBO

pebo-202601260000318300FALSE00003183002025-10-272025-10-27

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): January 26, 2026 (January 20, 2026)

PEOPLES BANCORP INC.

(Exact name of Registrant as specified in its charter)

Ohio000-1677231-0987416 (State or other jurisdiction(Commission File(I.R.S. Employer of incorporation)Number)Identification Number)

138 Putnam Street, PO Box 738 Marietta,Ohio45750-0738 (Address of principal executive offices)(Zip Code)

Registrant's telephone number, including area code:(740)373-3155

Not applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common shares, without par valuePEBOThe Nasdaq Stock Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02     Results of Operations and Financial Condition

On January 20, 2026, management of Peoples Bancorp Inc. (“Peoples”) conducted a facilitated conference call at approximately 11:00 a.m., Eastern Standard Time, to discuss results of operations for the quarter and fiscal year ended December 31, 2025. A replay of the conference call audio will be available on Peoples’ website, www.peoplesbancorp.com, in the “Investor Relations” section for one year. A copy of the transcript of the conference call is included as Exhibit 99.1 to this Current Report on Form 8-K. The information contained in this Item 2.02 and Exhibit 99.1 included with this Current Report on Form 8-K, is being furnished pursuant to Item 2.02 and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that Section, nor shall such information be deemed to be incorporated by reference in any registration statement or other document filed under the Securities Act of 1933, as amended, or the Exchange Act, except as otherwise stated in such filing. During the conference call, management referred to non-Generally Accepted Accounting Principles ("US GAAP") financial measures that are used by management to provide information useful to investors in understanding Peoples' operating performance and trends, and to facilitate comparisons with the performance of Peoples' peers. The following tables show the differences between the non-US GAAP financial measures referred to during the conference call and the most directly comparable US GAAP-based financial measures.

Three Months EndedFor the Year Ended December 31,September 30,December 31,December 31, (Dollars in thousands)20252025202420252024

Efficiency ratio: Total non-interest expense$71,294 $69,894 $70,503 $282,337 $273,816 Less: amortization of other intangible assets2,210 2,211 2,800 8,845 11,161 Adjusted total non-interest expense69,084 67,683 67,703 273,492 262,655

Total non-interest income26,272 23,827 25,089 104,078 99,366

Less: net (loss) gain on investment securities(77)(2,580)12 (2,659)(416) Less: net loss on asset disposals and other transactions(1,908)(478)(1,746)(3,027)(3,310) Total non-interest income, excluding net gains and losses28,257 26,885 26,823 109,764 103,092

Net interest income91,049 91,349 86,536 355,230 348,701 Add: fully tax-equivalent adjustment (a)266 279 286 1,108 1,308 Net interest income on a fully tax-equivalent basis91,315 91,628 86,822 356,338 350,009

Adjusted revenue$119,572 $118,513 $113,645 $466,102 $453,101

Efficiency ratio57.78 %57.11 %59.57 %58.68 %57.97 %

(a) Tax effect is calculated using a 21% statutory federal corporate income tax rate.

At or For the Three Months Ended December 31,September 30,June 30,March 31,December 31, (Dollars in thousands, except per share data)20252025202520252024

Tangible equity: Total

pebo-202601200000318300FALSE00003183002026-01-202026-01-20

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): January 20, 2026

PEOPLES BANCORP INC.

(Exact name of Registrant as specified in its charter)

Ohio000-1677231-0987416 (State or other jurisdiction(Commission File(I.R.S. Employer of incorporation)Number)Identification Number)

138 Putnam Street, PO Box 738 Marietta,Ohio45750-0738 (Address of principal executive offices)(Zip Code)

Registrant's telephone number, including area code:(740)373-3155

Not applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common shares, without par valuePEBOThe Nasdaq Stock Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐ 1

Item 2.02     Results of Operation and Financial Condition.

On January 20, 2026, Peoples Bancorp Inc. ("Peoples") issued a news release regarding its financial results for the fourth quarter of 2025. A copy of the news release is attached as Exhibit 99.1 to this Current Report on Form 8-K.

Peoples also provided electronic presentation slides that will be used in connection with its conference call to discuss earnings. A copy of the electronic slides is attached as Exhibit 99.2 to this Current Report on Form 8-K.

Conference Call to Discuss Earnings: Peoples will conduct a facilitated conference call to discuss fourth quarter of 2025 results of operations today at 11:00 a.m., Eastern Daylight Time, with members of Peoples' executive management participating. Analysts, media and individual investors are invited to participate in the conference call by calling (866) 890-9285. A simultaneous webcast of the conference call audio and earnings call presentation will be available online via the “Investor Relations” section of Peoples' website, www.peoplesbancorp.com.  Participants are encouraged to call or sign in at least 15 minutes prior to the scheduled conference call time to ensure participation and, if required, to download and install the necessary software. A replay of the call will be available on Peoples' website in the “Investor Relations” section for one year.

Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

On January 15, 2026, Peoples Bancorp Inc. (“Peoples”) received notice that Douglas V. Wyatt intends to retire from his position as Executive Vice President, Chief Commercial Banking Officer, of Peoples effective April 3, 2026. Mr. Wyatt will also be retiring from his position as Executive Vice President, Chief Commercial Banking Officer, of Peoples’ banking subsidiary, Peoples Bank.

Item 8.01     Other Events

Declaration of Dividend:

On January 20, 2026, Peoples issued a news release announcing that the Board of Directors declared a quarterly dividend of $0.41 per common share on January 19, 2026. A copy of the news release is included as Exhibit 99.3 to this Current Report on Form 8-K.

Officer Election:

On January 16, 2026, Peoples Bancorp Inc. (“Peoples”) issued a news release announcing that the Boards of Directors of Peoples and its banking subsidiary, Peoples Bank, elected Ron J. Majka to the position of Executive Vice President, Chief Commercial Banking Officer, of Peoples and Peoples Bank. Mr. Majka will assume these offices effective April 4, 2026. A copy of the news release issued by Peoples is filed with this Current Report on Form 8-K as Exhibit 99.4 and incorporated herein by reference.

Mr. Majka will succeed Douglas V. Wyatt, who has served as Executive Vice President, Chief Commercial Banking Officer, of Peoples and Peoples Bank since 2017. On January 15, 2026, Peoples

pebo-202510270000318300FALSE00003183002025-10-272025-10-27

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): October 27, 2025 (October 21, 2025)

PEOPLES BANCORP INC.

(Exact name of Registrant as specified in its charter)

Ohio000-1677231-0987416 (State or other jurisdiction(Commission File(I.R.S. Employer of incorporation)Number)Identification Number)

138 Putnam Street, PO Box 738 Marietta,Ohio45750-0738 (Address of principal executive offices)(Zip Code)

Registrant's telephone number, including area code:(740)373-3155

Not applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common shares, without par valuePEBOThe Nasdaq Stock Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02     Results of Operations and Financial Condition

On October 21, 2025, management of Peoples Bancorp Inc. (“Peoples”) conducted a facilitated conference call at approximately 11:00 a.m., Eastern Standard Time, to discuss results of operations for the quarter ended September 30, 2025. A replay of the conference call audio will be available on Peoples’ website, www.peoplesbancorp.com, in the “Investor Relations” section for one year. A copy of the transcript of the conference call is included as Exhibit 99.1 to this Current Report on Form 8-K. The information contained in this Item 2.02 and Exhibit 99.1 included with this Current Report on Form 8-K, is being furnished pursuant to Item 2.02 and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that Section, nor shall such information be deemed to be incorporated by reference in any registration statement or other document filed under the Securities Act of 1933, as amended, or the Exchange Act, except as otherwise stated in such filing. During the conference call, management referred to non-Generally Accepted Accounting Principles ("US GAAP") financial measures that are used by management to provide information useful to investors in understanding Peoples' operating performance and trends, and to facilitate comparisons with the performance of Peoples' peers. The following tables show the differences between the non-US GAAP financial measures referred to during the conference call and the most directly comparable US GAAP-based financial measures.

Three Months EndedNine Months Ended September 30,June 30,September 30,September 30, (Dollars in thousands)20252025202420252024

Efficiency ratio: Total non-interest expense$69,894 $70,362 $66,090 $211,043 $203,313 Less: amortization of other intangible assets2,211 2,211 2,786 6,635 8,361 Adjusted total non-interest expense67,683 68,151 63,304 204,408 194,952

Total non-interest income23,827 26,880 24,794 77,806 74,277

Less: net loss on investment securities(2,580)— (74)(2,582)(428) Less: net loss on asset disposals and other transactions(478)(280)(795)(1,119)(1,564) Total non-interest income, excluding net gains and losses26,885 27,160 25,663 81,507 76,269

Net interest income91,349 87,577 88,912 264,181 262,165 Add: fully tax-equivalent adjustment (a)279 280 318 842 1,022 Net interest income on a fully tax-equivalent basis91,628 87,857 89,230 265,023 263,187

Adjusted revenue$118,513 $115,017 $114,893 $346,530 $339,456

Efficiency ratio57.11 %59.25 %55.10 %58.99 %57.43 %

(a) Tax effect is calculated using a 21% statutory federal corporate income tax rate.

At or For the Three Months Ended September 30,June 30,March 31,December 31,September 30, (Dollars in thousands, except per share data)20252025202420242024

Tangible equity: Total stockholders' equity$1,182,776 $1,

pebo-202510210000318300FALSE00003183002025-10-212025-10-21

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): October 21, 2025

PEOPLES BANCORP INC.

(Exact name of Registrant as specified in its charter)

Ohio000-1677231-0987416 (State or other jurisdiction(Commission File(I.R.S. Employer of incorporation)Number)Identification Number)

138 Putnam Street, PO Box 738 Marietta,Ohio45750-0738 (Address of principal executive offices)(Zip Code)

Registrant's telephone number, including area code:(740)373-3155

Not applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common shares, without par valuePEBOThe Nasdaq Stock Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐ 1

Item 2.02     Results of Operation and Financial Condition.

On October 21, 2025 Peoples Bancorp Inc. ("Peoples") issued a news release regarding its financial results for the third quarter of 2025. A copy of the news release is attached as Exhibit 99.1 to this Current Report on Form 8-K.

Peoples also provided electronic presentation slides that will be used in connection with its conference call to discuss earnings. A copy of the electronic slides is attached as Exhibit 99.2 to this Current Report on Form 8-K.

Conference Call to Discuss Earnings: Peoples will conduct a facilitated conference call to discuss third quarter of 2025 results of operations today at 11:00 a.m., Eastern Daylight Time, with members of Peoples' executive management participating. Analysts, media and individual investors are invited to participate in the conference call by calling (866) 890-9285. A simultaneous webcast of the conference call audio and earnings call presentation will be available online via the “Investor Relations” section of Peoples' website, www.peoplesbancorp.com.  Participants are encouraged to call or sign in at least 15 minutes prior to the scheduled conference call time to ensure participation and, if required, to download and install the necessary software. A replay of the call will be available on Peoples' website in the “Investor Relations” section for one year.

Item 8.01     Other Events

On October 21, 2025, Peoples issued a news release announcing that the Board of Directors declared a quarterly dividend of $0.41 per common share on October 20, 2025. A copy of the news release is included as Exhibit 99.3 to this Current Report on Form 8-K.

Item 9.01     Financial Statements and Exhibits

a) Financial statements of businesses acquired No response required.

b) Pro forma financial information No response required.

c) Exhibits See Index to Exhibits on Page 3.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

2

PEOPLES BANCORP INC.

Date:October 21, 2025By:/s/KATIE BAILEY Katie Bailey

Executive Vice President, Chief Financial Officer and Treasurer

3

INDEX TO EXHIBITS

Exhibit NumberDescription 99.1 News Release issued by Peoples Bancorp Inc. on October 21, 2025

99.2 News Release issued by Peoples Bancorp Inc. on October 21, 2025

99.3 News Release issued by Peoples Bancorp Inc. on October 21, 2025

104Cover Page Interactive Data File (the cover page XBRL tags are embedded within the Inline XBRL document)

4

pebo-202507280000318300FALSE00003183002025-07-282025-07-28

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): July 28, 2025 (July 22, 2025)

PEOPLES BANCORP INC.

(Exact name of Registrant as specified in its charter)

Ohio000-1677231-0987416 (State or other jurisdiction(Commission File(I.R.S. Employer of incorporation)Number)Identification Number)

138 Putnam Street, PO Box 738 Marietta,Ohio45750-0738 (Address of principal executive offices)(Zip Code)

Registrant's telephone number, including area code:(740)373-3155

Not applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common shares, without par valuePEBOThe Nasdaq Stock Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02     Results of Operations and Financial Condition

On July 22, 2025, management of Peoples Bancorp Inc. (“Peoples”) conducted a facilitated conference call at approximately 11:00 a.m., Eastern Standard Time, to discuss results of operations for the quarter ended June 30, 2025. A replay of the conference call audio will be available on Peoples’ website, www.peoplesbancorp.com, in the “Investor Relations” section for one year. A copy of the transcript of the conference call is included as Exhibit 99.1 to this Current Report on Form 8-K. The information contained in this Item 2.02 and Exhibit 99.1 included with this Current Report on Form 8-K, is being furnished pursuant to Item 2.02 and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that Section, nor shall such information be deemed to be incorporated by reference in any registration statement or other document filed under the Securities Act of 1933, as amended, or the Exchange Act, except as otherwise stated in such filing. During the conference call, management referred to non-Generally Accepted Accounting Principles ("US GAAP") financial measures that are used by management to provide information useful to investors in understanding Peoples' operating performance and trends, and to facilitate comparisons with the performance of Peoples' peers. The following tables show the differences between the non-US GAAP financial measures referred to during the conference call and the most directly comparable US GAAP-based financial measures.

Three Months EndedSix Months Ended June 30,March 31,June 30,June 30, (Dollars in thousands)20252025202420252024

Efficiency ratio: Total non-interest expense$70,362 $70,787 $68,758 $141,149 $137,223 Less: amortization of other intangible assets2,211 2,213 2,787 4,424 5,575 Adjusted total non-interest expense68,151 68,574 65,971 136,725 131,648

Total non-interest income26,880 27,099 23,704 53,979 49,483

Less: net loss on investment securities— (2)(353)(2)(354) Less: net loss on asset disposals and other transactions(280)(361)(428)(641)(769) Total non-interest income, excluding net gains and losses27,160 27,462 24,485 54,622 50,606

Net interest income87,577 85,255 86,613 172,832 173,253 Add: fully tax-equivalent adjustment (a)280 283 352 563 705 Net interest income on a fully tax-equivalent basis87,857 85,538 86,965 173,395 173,958

Adjusted revenue$115,017 $113,000 $111,450 $228,017 $224,564

Efficiency ratio59.25 %60.68 %59.19 %59.96 %58.62 %

(a) Tax effect is calculated using a 21% statutory federal corporate income tax rate.

At or For the Three Months Ended June 30,March 31,December 31,September 30,June 30, (Dollars in thousands, except per share data)20252025202420242024

Tangible equity: Total stockholders' equity$1,153,350 $1,137,821 $1,111,590 $1,124,972 $1,077,833 Less:

pebo-202507220000318300FALSE00003183002025-07-222025-07-22

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): July 22, 2025

PEOPLES BANCORP INC.

(Exact name of Registrant as specified in its charter)

Ohio000-1677231-0987416 (State or other jurisdiction(Commission File(I.R.S. Employer of incorporation)Number)Identification Number)

138 Putnam Street, PO Box 738 Marietta,Ohio45750-0738 (Address of principal executive offices)(Zip Code)

Registrant's telephone number, including area code:(740)373-3155

Not applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common shares, without par valuePEBOThe Nasdaq Stock Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐ 1

Item 2.02     Results of Operation and Financial Condition.

On July 22, 2025 Peoples Bancorp Inc. ("Peoples") issued a news release regarding its financial results for the second quarter of 2025. A copy of the news release is attached as Exhibit 99.1 to this Current Report on Form 8-K.

Peoples also provided electronic presentation slides that will be used in connection with its conference call to discuss earnings. A copy of the electronic slides is attached as Exhibit 99.2 to this Current Report on Form 8-K.

Conference Call to Discuss Earnings: Peoples will conduct a facilitated conference call to discuss second quarter of 2025 results of operations today at 11:00 a.m., Eastern Daylight Time, with members of Peoples' executive management participating. Analysts, media and individual investors are invited to participate in the conference call by calling (866) 890-9285. A simultaneous webcast of the conference call audio and earnings call presentation will be available online via the “Investor Relations” section of Peoples' website, www.peoplesbancorp.com.  Participants are encouraged to call or sign in at least 15 minutes prior to the scheduled conference call time to ensure participation and, if required, to download and install the necessary software. A replay of the call will be available on Peoples' website in the “Investor Relations” section for one year.

Item 8.01     Other Events

On July 22, 2025, Peoples issued a news release announcing that the Board of Directors declared a quarterly dividend of $0.41 per common share on July 21, 2025. A copy of the news release is included as Exhibit 99.3 to this Current Report on Form 8-K.

Item 9.01     Financial Statements and Exhibits

a) Financial statements of businesses acquired No response required.

b) Pro forma financial information No response required.

c) Exhibits See Index to Exhibits on Page 3.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

2

PEOPLES BANCORP INC.

Date:July 22, 2025By:/s/KATIE BAILEY Katie Bailey

Executive Vice President, Chief Financial Officer and Treasurer

3

INDEX TO EXHIBITS

Exhibit NumberDescription 99.1 News Release issued by Peoples Bancorp Inc. on July 22, 2025

99.2 News Release issued by Peoples Bancorp Inc. on July 22, 2025

99.3 News Release issued by Peoples Bancorp Inc. on July 22, 2025

104Cover Page Interactive Data File (the cover page XBRL tags are embedded within the Inline XBRL document)

4

pebo-202504280000318300FALSE00003183002025-04-282025-04-28

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): April 28, 2025 (April 22, 2025)

PEOPLES BANCORP INC.

(Exact name of Registrant as specified in its charter)

Ohio000-1677231-0987416 (State or other jurisdiction(Commission File(I.R.S. Employer of incorporation)Number)Identification Number)

138 Putnam Street, PO Box 738 Marietta,Ohio45750-0738 (Address of principal executive offices)(Zip Code)

Registrant's telephone number, including area code:(740)373-3155

Not applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common shares, without par valuePEBOThe Nasdaq Stock Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02     Results of Operations and Financial Condition

On April 22, 2025, management of Peoples Bancorp Inc. (“Peoples”) conducted a facilitated conference call at approximately 11:00 a.m., Eastern Standard Time, to discuss results of operations for the quarter ended March 31, 2025. A replay of the conference call audio will be available on Peoples’ website, www.peoplesbancorp.com, in the “Investor Relations” section for one year. A copy of the transcript of the conference call is included as Exhibit 99.1 to this Current Report on Form 8-K. The information contained in this Item 2.02 and Exhibit 99.1 included with this Current Report on Form 8-K, is being furnished pursuant to Item 2.02 and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that Section, nor shall such information be deemed to be incorporated by reference in any registration statement or other document filed under the Securities Act of 1933, as amended, or the Exchange Act, except as otherwise stated in such filing. During the conference call, management referred to non-Generally Accepted Accounting Principles ("US GAAP") financial measures that are used by management to provide information useful to investors in understanding Peoples' operating performance and trends, and to facilitate comparisons with the performance of Peoples' peers. The following tables show the differences between the non-US GAAP financial measures referred to during the conference call and the most directly comparable US GAAP-based financial measures.

Three Months Ended March 31,December 31,March 31, (Dollars in thousands)202520242024

Efficiency ratio: Total non-interest expense$70,787 $70,503 $68,465 Less: amortization of other intangible assets2,213 2,800 2,788 Adjusted total non-interest expense68,574 67,703 65,677

Total non-interest income27,099 25,089 25,779

Less: net loss on investment securities(2)12 (1) Less: net loss on asset disposals and other transactions(361)(1,746)(341) Total non-interest income, excluding net gains and losses27,462 26,823 26,121

Net interest income85,255 86,536 86,640 Add: fully tax-equivalent adjustment (a)283 286 354 Net interest income on a fully tax-equivalent basis85,538 86,822 86,994

Adjusted revenue$113,000 $113,645 $113,115

Efficiency ratio60.68 %59.57 %58.06 %

(a) Tax effect is calculated using a 21% statutory federal corporate income tax rate.

At or For the Three Months Ended March 31,December 31,September 30,June 30,March 31, (Dollars in thousands, except per share data)20252024202420242024

Tangible equity: Total stockholders' equity$1,137,821 $1,111,590 $1,124,972 $1,077,833 $1,062,002 Less: goodwill and other intangible assets400,099 402,422 403,922 406,417 409,285 Tangible equity$737,722 $709,168 $721,050 $671,416 $652,717

Tangible assets: Total assets$9,246,000 $9,254,2

pebo-202504220000318300FALSE00003183002025-04-222025-04-22

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): April 22, 2025

PEOPLES BANCORP INC.

(Exact name of Registrant as specified in its charter)

Ohio000-1677231-0987416 (State or other jurisdiction(Commission File(I.R.S. Employer of incorporation)Number)Identification Number)

138 Putnam Street, PO Box 738 Marietta,Ohio45750-0738 (Address of principal executive offices)(Zip Code)

Registrant's telephone number, including area code:(740)373-3155

Not applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common shares, without par valuePEBOThe Nasdaq Stock Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐ 1

Item 2.02     Results of Operation and Financial Condition.

On April 22, 2025 Peoples Bancorp Inc. ("Peoples") issued a news release regarding its financial results for the first quarter of 2025. A copy of the news release is attached as Exhibit 99.1 to this Current Report on Form 8-K.

Peoples also provided electronic presentation slides that will be used in connection with its conference call to discuss earnings. A copy of the electronic slides is attached as Exhibit 99.2 to this Current Report on Form 8-K.

Conference Call to Discuss Earnings: Peoples will conduct a facilitated conference call to discuss first quarter of 2025 results of operations today at 11:00 a.m., Eastern Daylight Time, with members of Peoples' executive management participating. Analysts, media and individual investors are invited to participate in the conference call by calling (866) 890-9285. A simultaneous webcast of the conference call audio and earnings call presentation will be available online via the “Investor Relations” section of Peoples' website, www.peoplesbancorp.com.  Participants are encouraged to call or sign in at least 15 minutes prior to the scheduled conference call time to ensure participation and, if required, to download and install the necessary software. A replay of the call will be available on Peoples' website in the “Investor Relations” section for one year.

Item 8.01     Other Events

On April 22, 2025, Peoples issued a news release announcing that the Board of Directors declared a quarterly dividend of $0.41 per common share on April 21, 2025. A copy of the news release is included as Exhibit 99.3 to this Current Report on Form 8-K.

Item 9.01     Financial Statements and Exhibits

a) Financial statements of businesses acquired No response required.

b) Pro forma financial information No response required.

c) Exhibits See Index to Exhibits on Page 3.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

2

PEOPLES BANCORP INC.

Date:April 22, 2025By:/s/KATIE BAILEY Katie Bailey

Executive Vice President, Chief Financial Officer and Treasurer

3

INDEX TO EXHIBITS

Exhibit NumberDescription 99.1 News Release issued by Peoples Bancorp Inc. on April 22, 2025

99.2 News Release issued by Peoples Bancorp Inc. on April 22, 2025

99.3 News Release issued by Peoples Bancorp Inc. on April 22, 2025

104Cover Page Interactive Data File (the cover page XBRL tags are embedded within the Inline XBRL document)

4

pebo-202501270000318300FALSE00003183002025-01-272025-01-27

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): January 27, 2025 (January 21, 2025)

PEOPLES BANCORP INC.

(Exact name of Registrant as specified in its charter)

Ohio000-1677231-0987416 (State or other jurisdiction(Commission File(I.R.S. Employer of incorporation)Number)Identification Number)

138 Putnam Street, PO Box 738 Marietta,Ohio45750-0738 (Address of principal executive offices)(Zip Code)

Registrant's telephone number, including area code:(740)373-3155

Not applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common shares, without par valuePEBOThe Nasdaq Stock Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02     Results of Operations and Financial Condition

On January 21, 2025, management of Peoples Bancorp Inc. (“Peoples”) conducted a facilitated conference call at approximately 11:00 a.m., Eastern Standard Time, to discuss results of operations for the quarter and the full year ended December 31, 2024. A replay of the conference call audio will be available on Peoples’ website, www.peoplesbancorp.com, in the “Investor Relations” section for one year. A copy of the transcript of the conference call is included as Exhibit 99.1 to this Current Report on Form 8-K. The information contained in this Item 2.02 and Exhibit 99.1 included with this Current Report on Form 8-K, is being furnished pursuant to Item 2.02 and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that Section, nor shall such information be deemed to be incorporated by reference in any registration statement or other document filed under the Securities Act of 1933, as amended, or the Exchange Act, except as otherwise stated in such filing. During the conference call, management referred to non-Generally Accepted Accounting Principles ("US GAAP") financial measures that are used by management to provide information useful to investors in understanding Peoples' operating performance and trends, and to facilitate comparisons with the performance of Peoples' peers. The following tables show the differences between the non-US GAAP financial measures referred to during the conference call and the most directly comparable US GAAP-based financial measures.

Three Months EndedYear Ended December 31,September 30,December 31,December 31, (Dollars in thousands)20242024202320242023

Core non-interest expense:

Total non-interest expense$70,503 $66,090 $67,689 $273,816 $266,487

Less: acquisition-related expenses1,144 (892)1,276 169 16,970 Less: pension settlement charges— — — — 2,424

Add: COVID -19 Employee Retention Credit— — — — 548

Core non-interest expense$69,359 $66,982 $66,413 $273,647 $247,641

Three Months EndedYear Ended December 31,September 30,December 31,December 31, (Dollars in thousands)20242024202320242023

Efficiency ratio: Total non-interest expense$70,503 $66,090 $67,689 $273,816 $266,487 Less: amortization of other intangible assets2,800 2,786 3,271 11,161 11,222 Adjusted total non-interest expense67,703 63,304 64,418 262,655 255,265

Total non-interest income25,089 24,794 24,134 99,366 87,413

Less: net loss on investment securities12 (74)(1,592)(416)(3,700) Less: net loss on asset disposals and other transactions(1,746)(795)(619)(3,310)(2,837) Total non-interest income, excluding net gains and losses26,823 25,663 26,345 103,092 93,950

Net interest income86,536 88,912 88,369 348,701 339,374 Add: fully tax-equivalent adjustment (a)286 318 365 1,308 1,503 Net interest income on a fully tax-

pebo-202501210000318300FALSE00003183002025-01-212025-01-21

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): January 21, 2025

PEOPLES BANCORP INC.

(Exact name of Registrant as specified in its charter)

Ohio000-1677231-0987416 (State or other jurisdiction(Commission File(I.R.S. Employer of incorporation)Number)Identification Number)

138 Putnam Street, PO Box 738 Marietta,Ohio45750-0738 (Address of principal executive offices)(Zip Code)

Registrant's telephone number, including area code:(740)373-3155

Not applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common shares, without par valuePEBOThe Nasdaq Stock Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐ 1

Item 2.02     Results of Operation and Financial Condition.

On January 21, 2025 Peoples Bancorp Inc. ("Peoples") issued a news release regarding its financial results for the fourth quarter and full year of 2024. A copy of the news release is attached as Exhibit 99.1 to this Current Report on Form 8-K.

Peoples also provided electronic presentation slides that will be used in connection with its conference call to discuss earnings. A copy of the electronic slides is attached as Exhibit 99.2 to this Current Report on Form 8-K.

Conference Call to Discuss Earnings: Peoples will conduct a facilitated conference call to discuss fourth quarter and full year 2024 results of operations today at 11:00 a.m., Eastern Daylight Time, with members of Peoples' executive management participating. Analysts, media and individual investors are invited to participate in the conference call by calling (866) 890-9285. A simultaneous webcast of the conference call audio and earnings call presentation will be available online via the “Investor Relations” section of Peoples' website, www.peoplesbancorp.com.  Participants are encouraged to call or sign in at least 15 minutes prior to the scheduled conference call time to ensure participation and, if required, to download and install the necessary software. A replay of the call will be available on Peoples' website in the “Investor Relations” section for one year.

Item 8.01     Other Events

On January 21, 2025, Peoples issued a news release announcing that the Board of Directors declared a quarterly dividend of $0.40 per common share on January 20, 2025. A copy of the news release is included as Exhibit 99.3 to this Current Report on Form 8-K.

Item 9.01     Financial Statements and Exhibits

a) Financial statements of businesses acquired No response required.

b) Pro forma financial information No response required.

c) Exhibits See Index to Exhibits on Page 3.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

2

PEOPLES BANCORP INC.

Date:January 21, 2025By:/s/KATIE BAILEY Katie Bailey

Executive Vice President, Chief Financial Officer and Treasurer

3

INDEX TO EXHIBITS

Exhibit NumberDescription 99.1 News Release issued by Peoples Bancorp Inc. on January 21, 2025

99.2 News Release issued by Peoples Bancorp Inc. on January 21, 2025

99.3 News Release issued by Peoples Bancorp Inc. on January 21, 2025

104Cover Page Interactive Data File (the cover page XBRL tags are embedded within the Inline XBRL document)

4

pebo-202410280000318300FALSE00003183002024-10-282024-10-28

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): October 28, 2024 (October 22, 2024)

PEOPLES BANCORP INC.

(Exact name of Registrant as specified in its charter)

Ohio000-1677231-0987416 (State or other jurisdiction(Commission File(I.R.S. Employer of incorporation)Number)Identification Number)

138 Putnam Street, PO Box 738 Marietta,Ohio45750-0738 (Address of principal executive offices)(Zip Code)

Registrant's telephone number, including area code:(740)373-3155

Not applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common shares, without par valuePEBOThe Nasdaq Stock Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02     Results of Operations and Financial Condition

On October 22, 2024, management of Peoples Bancorp Inc. (“Peoples”) conducted a facilitated conference call at approximately 11:00 a.m., Eastern Standard Time, to discuss results of operations for the quarter and nine months ended September 30, 2024. A replay of the conference call audio will be available on Peoples’ website, www.peoplesbancorp.com, in the “Investor Relations” section for one year. A copy of the transcript of the conference call is included as Exhibit 99.1 to this Current Report on Form 8-K. The information contained in this Item 2.02 and Exhibit 99.1 included with this Current Report on Form 8-K, is being furnished pursuant to Item 2.02 and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that Section, nor shall such information be deemed to be incorporated by reference in any registration statement or other document filed under the Securities Act of 1933, as amended, or the Exchange Act, except as otherwise stated in such filing. During the conference call, management referred to non-Generally Accepted Accounting Principles ("US GAAP") financial measures that are used by management to provide information useful to investors in understanding Peoples' operating performance and trends, and to facilitate comparisons with the performance of Peoples' peers. The following tables show the differences between the non-US GAAP financial measures referred to during the conference call and the most directly comparable US GAAP-based financial measures.

Three Months EndedNine Months Ended September 30,June 30,September 30,September 30, (Dollars in thousands)20242024202320242023

Core non-interest expense:

Total non-interest expense$66,090 $68,758 $71,696 $203,313 $198,798

Less: acquisition-related expenses(662)— 4,434 (746)15,694 Less: pension settlement charges— — 2,424 — 2,424

Add: COVID -19 Employee Retention Credit— — — — 548

Core non-interest expense$66,752 $68,758 $64,838 $204,059 $181,228

Three Months EndedNine Months Ended September 30,June 30,September 30,September 30, (Dollars in thousands)20242024202320242023

Efficiency ratio: Total non-interest expense$66,090 $68,758 $71,696 $203,313 $198,798 Less: amortization of other intangible assets2,786 2,787 3,280 8,361 7,951 Adjusted total non-interest expense63,304 65,971 68,416 194,952 190,847

Total non-interest income24,794 23,704 23,204 74,277 63,279

Less: net loss on investment securities(74)(353)(7)(428)(2,108) Less: net loss on asset disposals and other transactions(795)(428)(307)(1,564)(2,218) Total non-interest income, excluding net gains and losses25,663 24,485 23,518 76,269 67,605

Net interest income88,912 86,613 93,274 262,165 251,005 Add: fully tax-equivalent adjustment (a)318 352 391 1,022 1,140 Net interest income on a fully t

pebo-202410220000318300FALSE00003183002024-10-222024-10-22

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): October 22, 2024

PEOPLES BANCORP INC.

(Exact name of Registrant as specified in its charter)

Ohio000-1677231-0987416 (State or other jurisdiction(Commission File(I.R.S. Employer of incorporation)Number)Identification Number)

138 Putnam Street, PO Box 738 Marietta,Ohio45750-0738 (Address of principal executive offices)(Zip Code)

Registrant's telephone number, including area code:(740)373-3155

Not applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common shares, without par valuePEBOThe Nasdaq Stock Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐ 1

Item 2.02     Results of Operation and Financial Condition.

On October 22, 2024 Peoples Bancorp Inc. ("Peoples") issued a news release regarding its financial results for the third quarter and full year of 2024. A copy of the news release is attached as Exhibit 99.1 to this Current Report on Form 8-K.

Peoples also provided electronic presentation slides that will be used in connection with its conference call to discuss earnings. A copy of the electronic slides is attached as Exhibit 99.2 to this Current Report on Form 8-K.

Conference Call to Discuss Earnings: Peoples will conduct a facilitated conference call to discuss third quarter and full year 2024 results of operations today at 11:00 a.m., Eastern Daylight Time, with members of Peoples' executive management participating. Analysts, media and individual investors are invited to participate in the conference call by calling (866) 890-9285. A simultaneous webcast of the conference call audio and earnings call presentation will be available online via the “Investor Relations” section of Peoples' website, www.peoplesbancorp.com.  Participants are encouraged to call or sign in at least 15 minutes prior to the scheduled conference call time to ensure participation and, if required, to download and install the necessary software. A replay of the call will be available on Peoples' website in the “Investor Relations” section for one year.

Item 8.01     Other Events

On October 22, 2024, Peoples issued a news release announcing that the Board of Directors declared a quarterly dividend of $0.40 per common share on October 21, 2024. A copy of the news release is included as Exhibit 99.3 to this Current Report on Form 8-K.

Item 9.01     Financial Statements and Exhibits

a) Financial statements of businesses acquired No response required.

b) Pro forma financial information No response required.

c) Exhibits See Index to Exhibits on Page 3.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

2

PEOPLES BANCORP INC.

Date:October 22, 2024By:/s/KATIE BAILEY Katie Bailey

Executive Vice President, Chief Financial Officer and Treasurer

3

INDEX TO EXHIBITS

Exhibit NumberDescription 99.1 News Release issued by Peoples Bancorp Inc. on October 22, 2024

99.2 News Release issued by Peoples Bancorp Inc. on October 22, 2024

99.3 News Release issued by Peoples Bancorp Inc. on October 22, 2024

104Cover Page Interactive Data File (the cover page XBRL tags are embedded within the Inline XBRL document)

4

pebo-202407260000318300FALSE00003183002024-07-262024-07-26

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): July 26, 2024 (July 23, 2024)

PEOPLES BANCORP INC.

(Exact name of Registrant as specified in its charter)

Ohio000-1677231-0987416 (State or other jurisdiction(Commission File(I.R.S. Employer of incorporation)Number)Identification Number)

138 Putnam Street, PO Box 738 Marietta,Ohio45750-0738 (Address of principal executive offices)(Zip Code)

Registrant's telephone number, including area code:(740)373-3155

Not applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common shares, without par valuePEBOThe Nasdaq Stock Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02     Results of Operations and Financial Condition

On July 23, 2024, management of Peoples Bancorp Inc. (“Peoples”) conducted a facilitated conference call at approximately 11:00 a.m., Eastern Standard Time, to discuss results of operations for the quarter and twelve months ended June 30, 2024. A replay of the conference call audio will be available on Peoples’ website, www.peoplesbancorp.com, in the “Investor Relations” section for one year. A copy of the transcript of the conference call is included as Exhibit 99.1 to this Current Report on Form 8-K. The information contained in this Item 2.02 and Exhibit 99.1 included with this Current Report on Form 8-K, is being furnished pursuant to Item 2.02 and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that Section, nor shall such information be deemed to be incorporated by reference in any registration statement or other document filed under the Securities Act of 1933, as amended, or the Exchange Act, except as otherwise stated in such filing. During the conference call, management referred to non-Generally Accepted Accounting Principles ("US GAAP") financial measures that are used by management to provide information useful to investors in understanding Peoples' operating performance and trends, and to facilitate comparisons with the performance of Peoples' peers. The following tables show the differences between the non-US GAAP financial measures referred to during the conference call and the most directly comparable US GAAP-based financial measures.

Three Months EndedSix Months Ended June 30,March 31,June 30,June 30, (Dollars in thousands)20242024202320242023

Core non-interest expense:

Total non-interest expense$68,758 $68,465 $70,623 $137,223 $127,102

Less: acquisition-related expenses— (84)10,709 (84)11,260

Add: COVID -19 Employee Retention Credit— — 548 — 548

Core non-interest expense$68,758 $68,549 $60,462 $137,307 $116,390

Three Months EndedSix Months Ended June 30,March 31,June 30,June 30, (Dollars in thousands)20242024202320242023

Efficiency ratio: Total non-interest expense$68,758 $68,465 $70,623 $137,223 $127,102 Less: amortization of other intangible assets2,787 2,788 2,800 5,575 4,671 Adjusted total non-interest expense65,971 65,677 67,823 131,648 122,431

Total non-interest income23,704 25,779 21,015 49,483 40,075

Less: net loss on investment securities(353)(1)(166)(354)(2,101) Less: net loss on asset disposals and other transactions(428)(341)(1,665)(769)(1,911) Total non-interest income, excluding net gains and losses24,485 26,121 22,846 50,606 44,087

Net interest income86,613 86,640 84,853 173,253 157,731 Add: fully tax-equivalent adjustment (a)352 352 386 705 738 Net interest income on a fully tax-equivalent basis86,965 86,992 85,239 173,958 158,469

Adjusted revenue$111,450 $113,113 $10

pebo-202407230000318300FALSE00003183002024-07-232024-07-23

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): July 23, 2024

PEOPLES BANCORP INC.

(Exact name of Registrant as specified in its charter)

Ohio000-1677231-0987416 (State or other jurisdiction(Commission File(I.R.S. Employer of incorporation)Number)Identification Number)

138 Putnam Street, PO Box 738 Marietta,Ohio45750-0738 (Address of principal executive offices)(Zip Code)

Registrant's telephone number, including area code:(740)373-3155

Not applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common shares, without par valuePEBOThe Nasdaq Stock Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐ 1

Item 2.02     Results of Operation and Financial Condition.

On July 23, 2024 Peoples Bancorp Inc. ("Peoples") issued a news release regarding its financial results for the second quarter and full year of 2024. A copy of the news release is attached as Exhibit 99.1 to this Current Report on Form 8-K.

Peoples also provided electronic presentation slides that will be used in connection with its conference call to discuss earnings. A copy of the electronic slides is attached as Exhibit 99.2 to this Current Report on Form 8-K.

Conference Call to Discuss Earnings: Peoples will conduct a facilitated conference call to discuss second quarter and full year 2024 results of operations today at 11:00 a.m., Eastern Daylight Time, with members of Peoples' executive management participating. Analysts, media and individual investors are invited to participate in the conference call by calling (866) 890-9285. A simultaneous webcast of the conference call audio and earnings call presentation will be available online via the “Investor Relations” section of Peoples' website, www.peoplesbancorp.com.  Participants are encouraged to call or sign in at least 15 minutes prior to the scheduled conference call time to ensure participation and, if required, to download and install the necessary software. A replay of the call will be available on Peoples' website in the “Investor Relations” section for one year.

Item 8.01     Other Events

On July 23, 2024, Peoples issued a news release announcing that the Board of Directors declared a quarterly dividend of $0.40 per common share on July 22, 2024. A copy of the news release is included as Exhibit 99.2 to this Current Report on Form 8-K.

Item 9.01     Financial Statements and Exhibits

a) Financial statements of businesses acquired No response required.

b) Pro forma financial information No response required.

c) Exhibits See Index to Exhibits on Page 3.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

2

PEOPLES BANCORP INC.

Date:July 23, 2024By:/s/KATIE BAILEY Katie Bailey

Executive Vice President, Chief Financial Officer and Treasurer

3

INDEX TO EXHIBITS

Exhibit NumberDescription 99.1 News Release issued by Peoples Bancorp Inc. on July 23, 2024

99.2 News Release issued by Peoples Bancorp Inc. on July 23, 2024

99.3 News Release issued by Peoples Bancorp Inc. on July 23, 2024

104Cover Page Interactive Data File (the cover page XBRL tags are embedded within the Inline XBRL document)

4

pebo-202404290000318300FALSE00003183002024-04-292024-04-29

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): April 29, 2024 (April 23, 2024)

PEOPLES BANCORP INC.

(Exact name of Registrant as specified in its charter)

Ohio000-1677231-0987416 (State or other jurisdiction(Commission File(I.R.S. Employer of incorporation)Number)Identification Number)

138 Putnam Street, PO Box 738 Marietta,Ohio45750-0738 (Address of principal executive offices)(Zip Code)

Registrant's telephone number, including area code:(740)373-3155

Not applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common shares, without par valuePEBOThe Nasdaq Stock Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02     Results of Operations and Financial Condition

On April 23, 2024, management of Peoples Bancorp Inc. (“Peoples”) conducted a facilitated conference call at approximately 11:00 a.m., Eastern Standard Time, to discuss results of operations for the quarter and twelve months ended March 31, 2024. A replay of the conference call audio will be available on Peoples’ website, www.peoplesbancorp.com, in the “Investor Relations” section for one year. A copy of the transcript of the conference call is included as Exhibit 99.1 to this Current Report on Form 8-K. The information contained in this Item 2.02 and Exhibit 99.1 included with this Current Report on Form 8-K, is being furnished pursuant to Item 2.02 and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that Section, nor shall such information be deemed to be incorporated by reference in any registration statement or other document filed under the Securities Act of 1933, as amended, or the Exchange Act, except as otherwise stated in such filing. During the conference call, management referred to non-Generally Accepted Accounting Principles ("US GAAP") financial measures that are used by management to provide information useful to investors in understanding Peoples' operating performance and trends, and to facilitate comparisons with the performance of Peoples' peers. The following tables show the differences between the non-US GAAP financial measures referred to during the conference call and the most directly comparable US GAAP-based financial measures.

Three Months Ended March 31,December 31,March 31, (Dollars in thousands)202420232023

Core non-interest expense:

Total non-interest expense$68,465 $67,689 $56,479

Less: acquisition-related expenses(84)1,276 551

Core non-interest expense$68,549 $66,413 $55,928

Three Months Ended March 31,December 31,March 31, (Dollars in thousands)202420232023

Efficiency ratio: Total non-interest expense$68,465 $67,689 $56,479 Less: amortization of other intangible assets2,788 3,271 1,871 Adjusted total non-interest expense65,677 64,418 54,608

Total non-interest income25,779 24,134 19,060

Less: net loss on investment securities(1)(1,592)(1,935) Less: net loss on asset disposals and other transactions(341)(619)(246) Total non-interest income, excluding net gains and losses26,121 26,345 21,241

Net interest income86,640 88,369 72,878 Add: fully tax-equivalent adjustment (a)400 414 399 Net interest income on a fully tax-equivalent basis87,040 88,783 73,277

Adjusted revenue$113,161 $115,128 $94,518

Efficiency ratio58.04 %55.95 %57.78 %

Efficiency ratio adjusted for non-core items:

Core non-interest expense$68,549 $66,413 $55,928

Less: amortization of other intangible assets2,788 3,271 1,871 Adjusted core non-interest expense65,761 63,142 54,057

Adjusted revenue$113,161 $11

pebo-202404230000318300FALSE00003183002024-04-232024-04-23

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): April 23, 2024

PEOPLES BANCORP INC.

(Exact name of Registrant as specified in its charter)

Ohio000-1677231-0987416 (State or other jurisdiction(Commission File(I.R.S. Employer of incorporation)Number)Identification Number)

138 Putnam Street, PO Box 738 Marietta,Ohio45750-0738 (Address of principal executive offices)(Zip Code)

Registrant's telephone number, including area code:(740)373-3155

Not applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common shares, without par valuePEBOThe Nasdaq Stock Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐ 1

Item 2.02     Results of Operation and Financial Condition.

On April 23, 2024 Peoples Bancorp Inc. ("Peoples") issued a news release regarding its financial results for the first quarter and full year of 2024. A copy of the news release is attached as Exhibit 99.1 to this Current Report on Form 8-K.

Conference Call to Discuss Earnings: Peoples will conduct a facilitated conference call to discuss first quarter and full year 2024 results of operations today at 11:00 a.m., Eastern Daylight Time, with members of Peoples' executive management participating. Analysts, media and individual investors are invited to participate in the conference call by calling (866) 890-9285. A simultaneous Webcast of the conference call audio will be available online via the “Investor Relations” section of Peoples' website, www.peoplesbancorp.com.  Participants are encouraged to call or sign in at least 15 minutes prior to the scheduled conference call time to ensure participation and, if required, to download and install the necessary software. A replay of the call will be available on Peoples' website in the “Investor Relations” section for one year.

Item 5.02     Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

As previously disclosed in the Current Report on Form 8-K of Peoples Bancorp Inc. (“Peoples”) filed on July 11, 2023, in connection with the retirement of Charles W. Sulerzyski on March 31, 2024, and the appointment, effective April 1, 2024, of Tyler J. Wilcox to serve as the next President and Chief Executive Officer of each of Peoples and Peoples’ banking subsidiary, Peoples Bank, Mr. Wilcox was to be elected as a director of each of Peoples and Peoples Bank to fill the vacancy created on each Board of Directors by the retirement of Mr. Sulerzyski. On April 22, 2024, the Board of Directors of Peoples elected Mr. Wilcox as a director of Peoples to serve for an initial term ending at Peoples’ 2024 Annual Meeting of Shareholders on April 25, 2024. On April 22, 2024, the Board of Directors of Peoples Bank elected Mr. Wilcox as a director of Peoples Bank. As an officer and employee of Peoples, Mr. Wilcox will receive no additional compensation for his service on the Boards of Directors of Peoples and Peoples Bank. Peoples has determined that neither Mr. Wilcox nor any of his immediate family members has had (or proposes to have) a direct or indirect interest in any transaction in which Peoples or any of Peoples’ subsidiaries was (or is proposed to be) a participant, that would be required to be disclosed under Item 404(a) of Securities and Exchange Commission Regulation S-K, excluding the employment relationship between Mr. Wilcox and Peoples.

Item 8.01     Other Events

On April 23, 2024, Peoples issued a news release announcing that the Board of Directors declared a quarterly dividend of $0.40 per common share on April 22, 2

pebo-202401260000318300FALSE00003183002024-01-262024-01-26

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): January 26, 2024 (January 23, 2024)

PEOPLES BANCORP INC.

(Exact name of Registrant as specified in its charter)

Ohio000-1677231-0987416 (State or other jurisdiction(Commission File(I.R.S. Employer of incorporation)Number)Identification Number)

138 Putnam Street, PO Box 738 Marietta,Ohio45750-0738 (Address of principal executive offices)(Zip Code)

Registrant's telephone number, including area code:(740)373-3155

Not applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common shares, without par valuePEBOThe Nasdaq Stock Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02     Results of Operations and Financial Condition

On January 23, 2024, management of Peoples Bancorp Inc. (“Peoples”) conducted a facilitated conference call at approximately 11:00 a.m., Eastern Standard Time, to discuss results of operations for the quarter and twelve months ended December 31, 2023. A replay of the conference call audio will be available on Peoples’ website, www.peoplesbancorp.com, in the “Investor Relations” section for one year. A copy of the transcript of the conference call is included as Exhibit 99.1 to this Current Report on Form 8-K. The information contained in this Item 2.02 and Exhibit 99.1 included with this Current Report on Form 8-K, is being furnished pursuant to Item 2.02 and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that Section, nor shall such information be deemed to be incorporated by reference in any registration statement or other document filed under the Securities Act of 1933, as amended, or the Exchange Act, except as otherwise stated in such filing. During the conference call, management referred to non-Generally Accepted Accounting Principles ("US GAAP") financial measures that are used by management to provide information useful to investors in understanding Peoples' operating performance and trends, and to facilitate comparisons with the performance of Peoples' peers. The following tables show the differences between the non-US GAAP financial measures referred to during the conference call and the most directly comparable US GAAP-based financial measures.

Three Months EndedYear Ended December 31,September 30,December 31,December 31, (Dollars in thousands)20232023202220232022

Core non-interest expense:

Total non-interest expense$67,689 $71,696 $53,366 $266,487 $207,147

Less: acquisition-related expenses1,276 4,434 702 16,970 3,016 Less: pension settlement charges— 2,424 46 2,424 185

Less: COVID-19-related expenses— — 2 — 134 Add: COVID -19 Employee Retention Credit— — — 548 —

Core non-interest expense$66,413 $64,838 $52,616 $247,641 $203,812

Three Months EndedYear Ended December 31,September 30,December 31,December 31, (Dollars in thousands)20232023202220232022

Efficiency ratio: Total non-interest expense$67,689 $71,696 $53,366 $266,487 $207,147 Less: amortization of other intangible assets3,271 3,280 1,998 11,222 7,763 Adjusted total non-interest expense64,418 68,416 51,368 255,265 199,384

Total non-interest income24,134 23,204 19,034 87,413 78,836

Less: net gain on investment securities— — — — — Less: net loss on investment securities(1,592)(7)(168)(3,700)(61) Less: net loss on asset disposals and other transactions(619)(307)(302)(2,837)(616) Total non-interest income, excluding net gains and losses26,345 23,518 19,504 93,950 79,513

Net interest income88,369 93,274 70,613 339,374 253,442 Add: f

pebo-202401230000318300FALSE00003183002024-01-232024-01-23

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): January 23, 2024

PEOPLES BANCORP INC.

(Exact name of Registrant as specified in its charter)

Ohio000-1677231-0987416 (State or other jurisdiction(Commission File(I.R.S. Employer of incorporation)Number)Identification Number)

138 Putnam Street, PO Box 738 Marietta,Ohio45750-0738 (Address of principal executive offices)(Zip Code)

Registrant's telephone number, including area code:(740)373-3155

Not applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common shares, without par valuePEBOThe Nasdaq Stock Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐ 1

Item 2.02     Results of Operation and Financial Condition.

On January 23, 2024 Peoples Bancorp Inc. ("Peoples") issued a news release regarding its financial results for the fourth quarter and full year of 2023. A copy of the news release is attached as Exhibit 99.1 to this Current Report on Form 8-K.

Conference Call to Discuss Earnings: Peoples will conduct a facilitated conference call to discuss fourth quarter and full year 2023 results of operations today at 11:00 a.m., Eastern Daylight Time, with members of Peoples' executive management participating. Analysts, media and individual investors are invited to participate in the conference call by calling (866) 890-9285. A simultaneous Webcast of the conference call audio will be available online via the “Investor Relations” section of Peoples' website, www.peoplesbancorp.com.  Participants are encouraged to call or sign in at least 15 minutes prior to the scheduled conference call time to ensure participation and, if required, to download and install the necessary software. A replay of the call will be available on Peoples' website in the “Investor Relations” section for one year.

Item 8.01     Other Events

On January 23, 2024, Peoples issued a news release announcing that the Board of Directors declared a quarterly dividend of $0.39 per common share on January 22, 2024. A copy of the news release is included as Exhibit 99.2 to this Current Report on Form 8-K.

Item 9.01     Financial Statements and Exhibits

a) Financial statements of businesses acquired No response required.

b) Pro forma financial information No response required.

c) Exhibits See Index to Exhibits on Page 3.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

PEOPLES BANCORP INC.

Date:January 23, 2024By:/s/KATIE BAILEY Katie Bailey

Executive Vice President, Chief Financial Officer and Treasurer

2

INDEX TO EXHIBITS

Exhibit NumberDescription 99.1 News Release issued by Peoples Bancorp Inc. on January 23, 2024

99.2 News Release issued by Peoples Bancorp Inc. on January 23, 2024

104Cover Page Interactive Data File (the cover page XBRL tags are embedded within the Inline XBRL document)

3

pebo-202310270000318300FALSE00003183002023-10-272023-10-27

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): October 27, 2023 (October 24, 2023)

PEOPLES BANCORP INC.

(Exact name of Registrant as specified in its charter)

Ohio000-1677231-0987416 (State or other jurisdiction(Commission File(I.R.S. Employer of incorporation)Number)Identification Number)

138 Putnam Street, PO Box 738 Marietta,Ohio45750-0738 (Address of principal executive offices)(Zip Code)

Registrant's telephone number, including area code:(740)373-3155

Not applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common shares, without par valuePEBOThe Nasdaq Stock Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02     Results of Operations and Financial Condition On October 24, 2023, management of Peoples Bancorp Inc. (“Peoples”) conducted a facilitated conference call at approximately 11:00 a.m., Eastern Daylight Time, to discuss results of operations for the quarter ended September 30, 2023. A replay of the conference call audio will be available on Peoples’ website, www.peoplesbancorp.com, in the “Investor Relations” section for one year. A copy of the transcript of the conference call is included as Exhibit 99.1 to this Current Report on Form 8-K. The information contained in this Item 2.02 and Exhibit 99.1 included with this Current Report on Form 8-K, is being furnished pursuant to Item 2.02 and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that Section, nor shall such information be deemed to be incorporated by reference in any registration statement or other document filed under the Securities Act of 1933, as amended, or the Exchange Act, except as otherwise stated in such filing. During the conference call, management referred to non-Generally Accepted Accounting Principles ("US GAAP") financial measures that are used by management to provide information useful to investors in understanding Peoples' operating performance and trends, and to facilitate comparisons with the performance of Peoples' peers. The following tables show the differences between the non-US GAAP financial measures referred to during the conference call and the most directly comparable US GAAP-based financial measures.

NON-US GAAP FINANCIAL MEASURES (Unaudited)

The following non-US GAAP financial measures used by Peoples provide information useful to investors in understanding Peoples' operating performance and trends, and facilitate comparisons with the performance of Peoples' peers. Peoples also uses the non-US GAAP financial measures for calculating incentive compensation. The following tables summarize the non-US GAAP financial measures derived from amounts reported in Peoples' consolidated financial statements:

Three Months EndedNine Months Ended September 30,June 30,September 30,September 30, (Dollars in thousands)20232023202220232022

Core non-interest expense:

Total non-interest expense$71,696 $70,623 $52,253 $198,798 $153,781

Less: acquisition-related expenses4,434 10,709 339 15,694 2,314 Less: pension settlement charges2,424 — 139 2,424 139

Less: COVID-19-related expenses— — 9 — 132 Add: COVID -19 Employee Retention Credit— 548 — 548 —

Core non-interest expense$64,838 $60,462 $51,766 $181,228 $151,196

NON-US GAAP FINANCIAL MEASURES (Unaudited) -- (Continued)

Three Months EndedNine Months Ended September 30,June 30,September 30,September 30, (Dollars in thousands)20232023202220232022

Efficiency ratio: Total non-interest expense71,696 $70,623 52,253 198,798 153,781 Less:

pebo-202310240000318300FALSE00003183002023-10-242023-10-24

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): October 24, 2023

PEOPLES BANCORP INC.

(Exact name of Registrant as specified in its charter)

Ohio000-1677231-0987416 (State or other jurisdiction(Commission File(I.R.S. Employer of incorporation)Number)Identification Number)

138 Putnam Street, PO Box 738 Marietta,Ohio45750-0738 (Address of principal executive offices)(Zip Code)

Registrant's telephone number, including area code:(740)373-3155

Not applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common Stock, no par valuePEBOThe Nasdaq Stock Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

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Item 2.02     Results of Operation and Financial Condition. On October 24, 2023 Peoples Bancorp Inc. ("Peoples") issued a news release regarding its financial results for the third quarter of 2023. A copy of the news release is attached as Exhibit 99.1 to this Current Report on Form 8-K. Conference Call to Discuss Earnings: Peoples will conduct a facilitated conference call to discuss third quarter 2023 results of operations today at 11:00 a.m., Eastern Daylight Time, with members of Peoples' executive management participating. Analysts, media and individual investors are invited to participate in the conference call by calling (866) 890-9285. A simultaneous webcast of the conference call audio will be available online via the “Investor Relations” section of Peoples' website, www.peoplesbancorp.com. Participants are encouraged to call or sign in at least 15 minutes prior to the scheduled conference call time to ensure participation and, if required, to download and install the necessary software. A replay of the call will be available on Peoples' website in the “Investor Relations” section for one year. Item 8.01     Other Events On October 24, 2023, Peoples issued a news release announcing that the Board of Directors declared a quarterly dividend of $0.39 per common share. A copy of the news release is included as Exhibit 99.2 to this Current Report on Form 8-K.

Item 9.01     Financial Statements and Exhibits

a) - c) Not applicable.

d) Exhibits See Index to Exhibits on Page 3.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

PEOPLES BANCORP INC.

Date:October 24, 2023By:/s/KATIE BAILEY Katie Bailey

Executive Vice President, Chief Financial Officer and Treasurer

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INDEX TO EXHIBITS

Exhibit NumberDescription 99.1 News Release issued by Peoples Bancorp Inc. on October 24, 2023

99.2 News Release issued by Peoples Bancorp Inc. on October 24, 2023

104Cover Page Interactive Data File (the cover page XBRL tags are embedded within the Inline XBRL document)

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