Executive Change · 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 26, 2021 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 2016A 5.25% Junior Subordinated Notes due 2076 SOJB New York Stock Exchange The Southern Company Series 2017B 5.25% Junior Subordinated Notes due 2077 SOJC New York Stock Exchange The Southern Company 2019 Series A Corporate Units SOLN 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 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 5.02. Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers. Upon recommendation of the Compensation and Management Succession Committee of the Board of Directors of The Southern Company (the “Company”), the Board of Directors of the Company approved The Southern Company 2021 Equity and Incentive Compensation Plan (the “Plan”), subject to stockholder approval. The Plan was approved by the Company’s stockholders at the Annual Meeting of Stockholders held on May 26, 2021. The Plan provides for awards of cash, stock options (including incentive stock options), stock appreciation rights, restricted stock, restricted stock units, performance shares, performance units, cash-based awards and certain other awards based on or related to shares of the Company’s common stock. The Plan will replace the Southern Company Omnibus Incentive Compensation Plan that was approved by the stockholders at the Annual Meeting of Stockholders held on May 25, 2011 (the “2011 Plan”). The Board of Directors may terminate or amend the Plan at any time; provided, however, that amendment of the Plan will be subject to stockholder approval in certain circumstances as required under the Plan. No grants will be made under the Plan on or after May 26, 2031. A total of 31,528,294 shares of common stock is available for grants under the Plan, representing 4,028,294 shares transferred from the 2011 Plan, plus 27,500,000 new shares. The number of shares available for grant is subject to adjustment under certain circumstances described in the Plan This description of the Plan is a summary only and is qualified by reference to the Plan, which is filed as Exhibit 10.1 hereto. A more complete description of the terms of the Plan can be found in “Item 3 - Approve the 2021 Equity and Incentive Compensation Plan (2021 Omnibus Plan)” on pages 94 to 102 of the Company’s definitive proxy statement filed with the Securities and Exchange Commission on April 12, 2021, which description is incorporated by reference herein. Item 5.07. Submission of Matters to a Vote of Security Holders. The Company held its Annual Meeting of Stockholders on May 26, 2021. Stockholders voted as follows on the 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 Against Abstentions Broker Non-Votes Janaki Akella 678,441,475  5,385,569  2,313,450  195,665,380  Juanita Powell Baranco 660,257,335  23,718,469  2,164,690  195,665,380  Henry A. Clark III 661,832,944  22,093,050  2,214,500  195,665,380  Anthony F. Earley, Jr. 678,006,046  5,886,484  2,247,964  195,665,380  Thomas A. Fanning 624,474,980  56,126,764  5,538,750  195,665,380  David J. Grain 678,070,606  5,815,742  2,254,146  195,665,380  Colette D. Honorable 669,663,655  14,370,873  2,105,966  195,665,380  Donald M. James 663,309,784  20,571,786  2,258,924  195,665,380  John D. Johns 676,431,518  7,510,726  2,198,250  195,665,380  Dale E. Klein 666,672,989  17,276,395  2,191,110  195,665,380  Ernest J. Moniz 652,441,257  29,594,748  4,104,489  195,665,380  William G. Smith, Jr. 649,741,712  34,212,456  2,186,326  195,665,380  E. Jenner Wood III 677,386,060  6,552,017  2,202,417  195,665,380  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 Against Abstentions Broker Non-Votes 648,563,546  32,055,527  5,521,421  195,665,380  3. The proposal to approve The Southern Company 2021 Equity and Incentive Compensation Plan was approved based upon the following votes: Votes For Votes Against Abstentions Broker Non-Votes 654,825,017  25,755,744  5,559,733  195,665,380  2 4. The proposal to ratify the appointment of Deloitte & Touche LLP as the Company’s independent registered public accounting firm for 2021 was approved based upon the following votes: Votes For Votes Against Abstentions Broker Non-Votes 871,666,470  7,819,809  2,319,595  N/A 5. 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 not approved based upon the following votes: Votes For Votes Against Abstentions Broker Non-Votes 670,269,931  11,575,229  4,295,334  195,665,380  Item 9.01. Financial Statement and Exhibits (d) Exhibits. 10.1 The Southern Company 2021 Equity and Incentive Compensation Plan, effective May 26, 2021. 104 Cover Page Interactive Data File – The cover page iXBRL tags are embedded within the inline XBRL document. 3 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. Date:   May 27, 2021 THE SOUTHERN COMPANY By /s/Melissa K. Caen Melissa K. Caen Assistant Secretary 4