USS Dianthus (SP-639)

USS Dianthus (SP-639) was a United States Navy patrol vessel in commission from 1917 to 1918.

Dianthus was built as a private motorboat of the same name by the Herreshoff Manufacturing Company at Bristol, Rhode Island, in 1913. On 21 May 1917, the U.S. Navy acquired her under a free lease from her owner, John P. Crozer of Upland, Pennsylvania, for use as a section patrol boat during World War I. She was commissioned as USS Dianthus (SP-639) on 26 May 1917 with Ensign J. J. Banner, USNRF, in command.

Assigned to the 4th Naval District, Dianthus performed patrol duty for the rest of World War I.

Dianthus was decommissioned on 27 November 1918 and returned to Crozer the same day.