Company: CCO
Filing Date: 2025-04-10
Form Type: DEFA14A
Source: 0001193125-25-077988
Chunk: 0

Company: Clear Channel Outdoor Holdings, Inc.
Filing Date: 2025-04-10
Form: DEFA14A
Chunk 0
---
UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 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                                     |

Clear Channel Outdoor Holdings, Inc. (Name of Registrant as Specified in Its Charter) (Name of Person(s) Filing Proxy Statement, if Other Than the Registrant) Payment of Filing Fee (Check all boxes that apply):

| ☒ |     | 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 |

| Online                                                                                                     
 Go to www.envisionreports.com/cco or scan the QR code – login details are located in the shaded bar below. |

Important Notice Regarding the Availability of Proxy Materials for the Annual Meeting of Stockholders of Clear Channel Outdoor Holdings, Inc. to be held on May 29, 2025 Under Securities and Exchange Commission rules, you are receiving this notice that the proxy materials for the annual stockholders’ meeting are available on the Internet. Follow the instructions below to view the materials and vote online or request a copy. The items to be voted on and location of the annual meeting are on the reverse side. Your vote is important! This communication presents only an overview of the more complete proxy materials that are available to you on the Internet. We encourage you to access and review all of the important information contained in the proxy materials before voting. The Proxy Statement and Annual Report are available at:

| www.envisionreports.com/cco |

| Easy Online Access – View your proxy materials and vote.                    
 Step 1: Go to www.envisionreports.com/cco.                                  
 Step 2: Click on Cast Your Vote or Request Materials.                       
 Step 3:�