USS Fli-Hawk (SP-550) was a United States Navy patrol vessel in commission from 1917 to 1919.

In 1917, the U.S. Navy acquired her under a free lease from her owner for use as a section patrol vessel during World War I.

Assigned to the 5th Naval District, Fli-Hawk operated on patrol duties in the Norfolk, Virginia, area for the rest of World War I.

On 31 December 1917, Fli-Hawk was getting underway when she collided with the steamer SS Gratitude in Norfolk Harbor.

Fli-Hawk sank three hours later, but was raised, repaired, and returned to service.