USS Cossatot (AO-77) was a United States Navy World War II Type T2-SE-A1 tanker which served as a fleet oiler.

Cossatot sortied as a part of TG 60.8, the logistics group for the 6th Fleet, for operations off Iwo Jima from 13 March to 12 April.

From 26 May until the official surrender by Japan on 15 August 1945, Cossatot operated out of Ulithi fueling various units of fast carrier TF 38, engaged in the final strikes against the Japanese homeland.

Reacquired in February 1948, she was transferred to the Military Sea Transportation Service on 1 October 1949 where she has served in a noncommissioned status under the Maritime Administration.

On 15 June 1968 Cossatot was damaged after a collision with the merchant vessel Copper State, in fog, off the coast of Santa Cruz, California.