Company: CHY
Filing Date: 2025-08-29
Form Type: 424B3
Source: 0001104659-25-085285
Chunk: 0

Company: CALAMOS CONVERTIBLE & HIGH INCOME FUND
Filing Date: 2025-08-29
Form: 424B3
Chunk 0
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Filed pursuant to Rule 424(b)(3)
File No. 333-285119

<div align='center'>CALAMOS CONVERTIBLE AND HIGH INCOME FUND

(the “Fund”)

Supplement dated September 1, 2025 to the CALAMOS ®FAMILY OF FUNDS (the “Funds”)

Statement of Additional Information, dated February 21, 2025, as supplemented</div>

This supplement updates certain information contained in the Statement of Additional Information noted above and should be attached to the Statement of Additional Information and retained for future reference.

Capitalized terms and certain other terms used in this supplement, unless otherwise defined in this supplement, have the meanings assigned to them in the Statement of Additional Information.

Effective September 1, 2025, the following changes are made to the
Statement of Additional Information:

| (1) | Effective September 1, 2025, John S. Koudounis, Hugh P. Armstrong and Jeffrey S. Phlegar were elected as trustees of the Trust.                                                                                                                                                        |
| (2) | Effective September 1, 2025, the section titled “Trustees Who Are Interested Persons of the Trust” under the “Management of the Fund” section beginning on page S-27 of the Statement of Additional Information is amended to include the following information about the new trustee: |

| NAME AND          
 YEAR OF           
 BIRTH             |     | POSITION(S)     
 AND             
 LENGTH OF       
 TIME            
 WITH THE        
 TRUST           |     | PORTFOLIOS 
    IN FUND 
   COMPLEX^ 
   OVERSEEN |     | PRINCIPAL                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
 OCCUPATION(S)                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
 DURING THE PAST                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
 5 YEARS AND OTHER                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
 DIRECTORSHIPS                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |     | EXPERIENCE,                                                                                                                                               
 QUALIFICATIONS,                                                                                                                                           
 ATTRIBUTES,                                                                                                                                               
 SKILLS FOR BOARD                                                                                                                                          
 MEMBERSHIP                                                                                                                                                |
| John S. Koudounis 
 (1966)            |     | Trustee (since  
 September 2025) |     |         70 |     | President (since February 2021) and Chief Executive Officer, Calamos Asset Management, Inc., Calamos Investments LLC, Calamos Advisors, Calamos Wealth Management LLC, and Calamos Financial Services LLC (since 2016); Chairman and Chief Executive Officer (since 2022), Calamos Antetok