Shareholder Vote

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 21, 2025 Commission File Number Registrant, State of Incorporation, Address and Telephone Number I.R.S. Employer Identification No. 1-3526 The Southern Company 58-0690070 (A Delaware Corporation) 30 Ivan Allen Jr. Boulevard, N.W . Atlanta , Georgia 30308 ( 404 ) 506-5000 The name and address of the registrant have not changed since the 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: Registrant Title of each class Trading Symbol(s) Name of each exchange on which registered The Southern Company Common Stock, par value $5 per share SO New York Stock Exchange The Southern Company Series 2017B 5.25% Junior Subordinated Notes due 2077 SOJC New York Stock Exchange The Southern Company Series 2020A 4.95% Junior Subordinated Notes due 2080 SOJD New York Stock Exchange The Southern Company Series 2020C 4.20% Junior Subordinated Notes due 2060 SOJE New York Stock Exchange The Southern Company Series 2021B 1.875% Fixed-to-Fixed Reset Rate Junior Subordinated Notes due 2081 SO 81 New York Stock Exchange The Southern Company Series 2025A 6.50% Junior Subordinated Notes due 2085 SOJF 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 5.07. Submission of Matters to a Vote of Security Holders. The Southern Company (the “Company”) held its Annual Meeting of Stockholders on May 21, 2025. Stockholders voted as follows on the eight matters presented for a vote: 1. The nominees for election to the Board of Directors were elected based on the following votes: Nominees Votes For % Votes Cast For Votes Against Abstentions Broker Non-Votes Janaki Akella 749,639,237 99.21% 5,944,364 1,941,368 182,350,030  Shantella E. Cooper 749,473,661 99.20% 6,080,664 1,970,644 182,350,030  Anthony F. Earley, Jr. 749,344,952 99.17% 6,296,000 1,884,017 182,350,030  James O. Etheredge 752,375,794 99.57% 3,249,469 1,899,706 182,350,030  David J. Grain 725,462,221 96.01% 30,158,017 1,904,731 182,350,030  Donald M. James 726,086,238 96.10% 29,500,982 1,937,749 182,350,030  John D. Johns 744,990,356 98.60% 10,614,859 1,919,754 182,350,030  Dale E. Klein 717,412,635 94.94% 38,206,883 1,905,451 182,350,030  David E. Meador 749,848,563 99.23% 5,816,010 1,860,396 182,350,030  William G. Smith, Jr. 726,178,553 96.10% 29,461,573 1,884,843 182,350,030  Kristine L. Svinicki 749,980,619 99.24% 5,726,445 1,817,905 182,350,030  Lizanne Thomas 747,738,634 98.95% 7,961,282 1,825,053 182,350,030  Christopher C. Womack 720,514,328 95.36% 35,067,353 1,943,288 182,350,030  2. The proposal to approve, on an advisory basis, the Company’s named executive officers’ compensation was approved based upon the following votes: Votes For % Votes Cast For Votes Against Abstentions Broker Non-Votes 703,548,379 93.44% 49,427,301 4,549,289 182,350,030 3. The proposal to ratify the appointment of Deloitte & Touche LLP as the Company’s independent registered public accounting firm for 2025 was approved based upon the following votes: Votes For % Votes Cast For Votes Against Abstentions Broker Non-Votes 912,246,021 97.28  % 25,535,434 2,093,544  N/A 4. The proposal to approve an amendment to the Company’s Restated Certificate of Incorporation to reduce the supermajority vote requirement to a majority vote, which pursuant to the Company’s Restated Certificate of Incorporation requires the affirmative vote of two-thirds of the issued and outstanding shares, was approved based upon the following votes: Votes For % Votes Cast For % Outstanding For Votes Against Abstentions Broker Non-Votes 745,722,382 98.85  % 67.78  % 8,672,817  3,129,770  182,350,030 5. The stockholder proposal regarding simple majority vote was not approved based upon the following votes: Votes For % Votes Cast For Votes Against Abstentions Broker Non-Votes 334,378,712 44.60  % 415,369,537 7,776,720 182,350,030 6. The stockholder proposal regarding disclosing assumptions underlying continued reliance on fossil fuel-based energy was not approved based upon the following votes: Votes For % Votes Cast For Votes Against Abstentions Broker Non-Votes 55,001,768 7.34  % 694,844,390 7,678,811 182,350,030 7. The stockholder proposal regarding conducting a net zero audit was not approved based upon the following votes: Votes For % Votes Cast For Votes Against Abstentions Broker Non-Votes 12,859,513 1.71  % 737,334,277 7,331,179 182,350,030 8. The stockholder proposal regarding a report on respecting workforce civil liberties was not approved based upon the following votes: Votes For % Votes Cast For Votes Against Abstentions Broker Non-Votes 11,233,860 1.50  % 738,347,843 7,943,266 182,350,030 [Item 9.01. Financial Statements and Exhibits. 2 Item 9.01. Financial Statements and Exhibits .  (d) Exhibits.   3.1 Certificate of Amendment to the Certificate of Incorporation of the Company, effective May 27, 2025.   104 Cover Page Interactive Data File – The cover page iXBRL tags are embedded within the inline XBRL document. 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. Date:   May 27, 2025 THE SOUTHERN COMPANY By /s/Melissa K. Caen Melissa K. Caen Assistant Secretary 4