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

History
United States
Name	USS Shrimp
Namesake	Previous name retained
Builder	Gas Engine and Power Company, Morris Heights, the Bronx, New York
Completed	1912
Acquired	14 May 1917
Commissioned	21 August 1917
Decommissioned	30 November 1918
Fate	Returned to owner 25 February 1919
Notes	Operated as private motorboat Shrimp 1912–1917 and from 1919
General characteristics
Type	Patrol vessel
Length	35 ft (11 m)
Beam	9 ft 6 in (2.90 m)
Complement	15
Armament	1 × machine gun

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. She was commissioned as USS Shrimp (SP-645) on 21 August 1917.

Shrimp was assigned to harbor patrol duty in Boston Harbor and local escort duty in the Boston area. 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.

Shrimp was decommissioned on 30 November 1918 and returned to Rudd on 25 February 1919.