Results of Operations · Bylaw Amendment

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): May 1, 2025 OLIN CORPORATION (Exact name of registrant as specified in its charter) Virginia 1-1070 13-1872319 (State or Other Jurisdiction of Incorporation) (Commission File Number) (IRS Employer Identification No.) 190 Carondelet Plaza, Suite 1530 Clayton, MO 63105 (Address of principal executive offices) (Zip Code) ( 314 ) 480-1400 (Registrant’s telephone number, including area code) (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 (see General Instruction A.2. below): ☐ 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 class Trading Symbol Name of each exchange on which registered Common Stock, $1.00 par value per share OLN New York Stock Exchange 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 May 1, 2025, Olin Corporation (“Olin”) issued a press release announcing financial results for the quarter ended March 31, 2025. Attached as Exhibit 99.1, and incorporated by reference, is a copy of Olin’s press release dated May 1, 2025. Item 5.03.    Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year. On May 1, 2025, the Board approved an amendment to Article II, Section 1 of Olin’s Bylaws to decrease the size of the Board from ten to nine directors, following the completion of Mr. C. Robert Bunch’s term on the Board. A copy of the amended Bylaws is filed as Exhibit 3.1 hereto and is incorporated by reference into this Item 5.03. Item 5.07.    Submission of Matters to a Vote of Security Holders. Olin’s 2025 annual meeting of shareholders was held on May 1, 2025. Of the 115,083,118 shares of Common Stock entitled to vote at such meeting, 105,021,493 shares were present for purposes of a quorum. The voting results for each of the three proposals submitted for vote by Olin’s shareholders are set forth below. Proposal 1 – Election of Directors The shareholders elected each of the nine nominees to the Board of Directors for a one-year term by the vote of the majority of votes cast, in accordance with Olin’s Bylaws. Votes For Votes Against Abstentions Broker Non-Votes Beverley A. Babcock 90,634,789 935,869 199,235 13,251,600 Edward M. Daly 90,901,505 668,411 199,977 13,251,600 Matthew S. Darnall 90,582,241 981,249 206,403 13,251,600 Kenneth T. Lane 90,506,541 1,053,192 210,160 13,251,600 Julie A. Piggott 90,540,704 1,023,033 206,156 13,251,600 Earl L. Shipp 90,269,973 1,295,826 204,094 13,251,600 William H. Weideman 90,498,394 1,051,162 220,337 13,251,600 W. Anthony Will 90,486,168 1,071,274 212,450 13,251,600 Carol A. Williams 90,687,338 904,991 177,564 13,251,600 Proposal 2 – Conduct an advisory vote to approve the compensation for named executive officers The shareholders gave an advisory approval of the compensation for named executive officers. Votes For Votes Against Abstentions Broker Non-Votes Proposal 2 86,249,070 5,235,229 285,594 13,251,600 Proposal 3 – Ratification of appointment of KPMG LLP as independent registered public accounting firm for 2025 The shareholders ratified the appointment of KPMG LLP as Olin’s independent registered public accounting firm for 2025. Votes For Votes Against Abstentions Broker Non-Votes Proposal 3 103,102,919 1,739,627 178,947 0 Item 7.01.    Regulation FD Disclosure. On May 1, 2025, Olin’s Board of Directors declared a quarterly dividend of $0.20 on each share of Olin common stock. The dividend is payable on June 13, 2025 to shareholders of record at the close of business on May 15, 2025. This marks Olin’s 394th consecutive quarterly dividend. Item 9.01.    Financial Statements and Exhibits. (d) Exhibit No. Exhibit 3.1 Bylaws of Olin Corporation, as amended effective May 1, 2025 99.1 Press Release announcing first quarter 202 5 earnings, dated May 1 , 2025 104 Cover Page Interactive Data File (embedded within the Inline XBRL document) SIGNATURE 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. OLIN CORPORATION By: /s/ Inchan Hwang Name: Inchan Hwang Title: Vice President, Deputy General Counsel and Secretary Date: May 1, 2025