| United States Fourth Fleet | |
|---|---|
 | |
| Active | 1943–1945 2008–present |
| Country | United States of America |
| Branch | United States Navy |
| Type | Fleet Command |
| Role | Direct Fleet Operations |
| Part of | U.S. Naval Forces Southern Command U.S. Southern Command (USSOUTHCOM) |
| Garrison/HQ | Naval Station Mayport |
| Commanders | |
| Current commander | Rear Admiral Carlos A. Sardiello |
The U.S. Fourth Fleet is a United States Navy numbered fleet. It is the Naval Component Command of U.S. Southern Command (USSOUTHCOM). The Fourth Fleet is headquartered at Naval Station Mayport in Jacksonville, Florida. It is responsible for U.S. Navy ships, aircraft and submarines operating in the Caribbean Sea, and the Atlantic and Pacific Oceans around Central and South America.