| Date of Report (Date of earliest event reported) | March 16, 2026 | |||||||
| Commission File Number | Registrant, State of Incorporation, Address and Telephone Number | I.R.S. Employer Identification No. | ||||||||||||||||||
| 1-3526 | The Southern Company | 58-0690070 | ||||||||||||||||||
☐ | 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)) | ||||
| 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 | ||||||||
| The Southern Company | 2025 Series A Corporate Units | SOMN | New York Stock Exchange | ||||||||
| Item 8.01. | Other Events. | ||||
| Item 9.01. | Financial Statements and Exhibits. | ||||
| (d) Exhibits. | |||||
| 1.3 | Underwriting Agreement relating to the Series 2026A Junior Subordinated Notes, dated March 16, 2026, among the Company and Citigroup Global Markets Inc., J.P. Morgan Securities LLC, Mizuho Securities USA LLC, Morgan Stanley & Co. LLC and U.S. Bancorp Investments, Inc., as representatives of the several Underwriters named in Schedule I thereto. | ||||
| 4.4 | |||||
| 4.8 | Form of the Series 2026A Junior Subordinated Note (included in Exhibit 4.4 above). | ||||
| 5.1 | |||||
| 8.1 | |||||
| 23.1 | Consent of Troutman Pepper Locke LLP (included in Exhibit 5.1 above). | ||||
| 23.2 | Consent of Troutman Pepper Locke LLP (included in Exhibit 8.1 above). | ||||
| 104 | Cover Page Interactive Data File – The cover page iXBRL tags are embedded within the inline XBRL document. | ||||
| Date: March 19, 2026 | THE SOUTHERN COMPANY | |||||||
| By | /s/Melissa K. Caen | |||||||
| Melissa K. Caen Assistant Secretary | ||||||||