USS Shrimp (SP-645) was a United States Navy patrol vessel in commission from 1917 to 1918.

Shrimp was built as a private motorboat of the same name by the Gas Engine and Power Company at Morris Heights in the Bronx, New York, in 1912.

On 14 May 1917, the U.S. Navy acquired her from her owner, H. W. D. Rudd of Boston, Massachusetts, for use as a section patrol boat during World War I.

Although twice reported lost at sea and once nearly destroyed by fire, Shrimp survived her misadventures and remained in service.

She eventually was reassigned to night patrol duty at the Fore River Shipyard in Quincy, Massachusetts, but soon was recalled for further harbor patrol duty in Boston Harbor.