Company: IONQ
Filing Date: 2025-10-10
Form Type: 424B5
Source: 0001193125-25-236452
Chunk: 54

Company: IonQ, Inc.
Filing Date: 2025-10-10
Form: 424B5
Chunk 54
---
 and
“IONQ.WS,” respectively. Each prospectus supplement will indicate whether the securities offered thereby will be listed on any securities exchange.

Investing in our securities involves risks. Please carefully read the information under the headings “ Risk Factors” beginning on page 4 of this prospectus and “Item 1A – Risk Factors” of our most recent report on Form 10-Kor 10-Qthat is incorporated by reference in this prospectus before you invest in our securities.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus. Any representation to the contrary is a criminal offense.

The date of this prospectus is February 26, 2025.

TABLE OF CONTENTS Page

| About this Prospectus               |     | ii |
| Prospectus Summary                  |     |  1 |
| Risk Factors                        |     |  4 |
| Forward-Looking                     
 Statements                          |     |  5 |
| Use of Proceeds                     |     |  6 |
| Selling Stockholders                |     |  7 |
| Description of Capital Stock        |     |  8 |
| Description of Debt Securities      |     |  9 |
| Description of Depositary Shares    |     | 17 |
| Description of Warrants             |     | 20 |
| Description of Subscription Rights  |     | 21 |
| Description of Purchase Contracts   |     | 22 |
| Description of Units                |     | 23 |
| Plan of Distribution                |     | 24 |
| Legal Matters                       |     | 27 |
| Experts                             |     | 27 |
| Where You Can Find More Information |     | 28 |
| Incorporation by Reference          |     | 29 |

i

ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement that we filed with the Securities and Exchange Commission, or the SEC, using a
“shelf” registration process. Under this shelf registration process, we or the selling stockholders may from time to time sell any combination of the securities described in this prospectus in one or more offerings.

This prospectus provides you with a general description of the securities that may be offered. Each time we or the selling stockholders sell
securities, we will provide one or more prospectus supplements that will contain specific information about the terms of the offering. The prospectus supplement may also add, update or