Company: ATO
Filing Date: 2025-12-19
Form Type: DEFA14A
Source: 0000731802-25-000077
Chunk: 0

Company: ATMOS ENERGY CORP
Filing Date: 2025-12-19
Form: DEFA14A
Chunk 0
---
### UNITED STATES

### SECURITIES AND EXCHANGE COMMISSION
<div align='center'>Washington, D.C. 20549</div>

#### SCHEDULE 14A
<div align='center'>Proxy Statement Pursuant to Section 14(a)
of the Securities Exchange Act of 1934
(Amendment No. )</div>

| Filed by the Registrant ☒                    |
| Filed by a Party other than the Registrant ☐ |

| Check the appropriate box: |     |                                             |     |   |     |                                                                                 |
| ☐                          |     | Preliminary Proxy Statement                 |     | ☐ |     | Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) |
| ☐                          |     | Definitive Proxy Statement                  |     |   |     |                                                                                 |
| ☒                          |     | Definitive Additional Materials             |     |   |     |                                                                                 |
| ☐                          |     | Soliciting Material Pursuant to §240.14a-12 |     |   |     |                                                                                 |

#### Atmos Energy Corporation
<div align='center'>(Name of Registrant as Specified in its Charter)</div>

<div align='center'>(Name of Person(s) Filing Proxy Statement, if other than the Registrant)</div>

| Payment of Filing Fee (Check the appropriate box): |     |                                                                                                      |
| ☒                                                  |     | No fee required.                                                                                     |
| ☐                                                  |     | Fee paid previously with preliminary materials.                                                      |
| ☐                                                  |     | Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11. |