| Submarine Squadron 4 | |
|---|---|
 | |
| Active | 1930–1995 1997–present |
| Country |  United States of America |
| Branch |  United States Navy |
| Type | Submarine Squadron |
| Size | Squadron |
| Part of | Submarine Group 2 |
| Garrison/HQ | Naval Submarine Base New London |
Submarine Squadron 4 ( SUBRON 4, also known as CSS-4) is a US Navy unit of submarines.
Raised by the United States Navy in 1930, since 9 July 1997, the squadron has been based at the Naval Submarine Base New London, Groton, Connecticut, United States of America.