Company: ATO
Filing Date: 2025-06-26
Form Type: 11-K
Source: 0000731802-25-000020
Chunk: 0

Company: ATMOS ENERGY CORP
Filing Date: 2025-06-26
Form: 11-K
Chunk 0
---
### UNITED STATES

### SECURITIES AND EXCHANGE COMMISSION

#### WASHINGTON, D.C. 20549

#### FORM 11-K
<div align='center'>FOR ANNUAL REPORTS OF EMPLOYEE STOCK PURCHASE, SAVINGS</div>

#### AND SIMILAR PLANS PURSUANT TO SECTION 15(d) OF

#### THE SECURITIES EXCHANGE ACT OF 1934
(Mark One)

| ý |     | ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 |

#### For the fiscal year ended December 31, 2024

#### OR
| ¨ |     | TRANSITION REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 |

#### For the transition period from

#### to

#### Commission File Number 33-57687

### ATMOS ENERGY CORPORATION RETIREMENT

### SAVINGS PLAN AND TRUST
<div align='center'>(Full title of the plan and the address of the

plan, if different from that of the issuer named below)</div>

### ATMOS ENERGY CORPORATION

#### Three Lincoln Centre, Suite 1800

#### 5430 LBJ Freeway

#### Dallas, Texas 75240
<div align='center'>(Name of issuer of the securities held pursuant to the plan and the</div>

#### address of its principal executive office)

### TABLE OF CONTENTS
|                                                                           |     |   Page 
 Number |
| Report of Independent Registered Public Accounting Firm                   |     |      2 |
| Audited Financial Statements:                                             |     |        |
| Statements of Net Assets Available for Benefits                           |     |      3 |
| Statement of Changes in Net Assets Available for Benefits                 |     |      4 |
| Notes to Financial Statements                                             |     |      5 |
| Supplemental Schedule:                                                    |     |        |
| Form 5500, Schedule H, Line 4i – Schedule of Assets (Held At End of Year) |     |     11 |
| Signatures                                                                |     |     12 |
| Exhibits Index                                                            |     |     13 |

<div align='center'>1</div>

### REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM
To the Participants and the Qualified Retirement Plans and Trusts Committee of the

Atmos Energy Corporation Retirement Savings Plan and Trust

#### Opinion on the Financial