USS PT-331 was a motor torpedo boat of the United States Navy. Boats of the PT type were small and fast, known by number, and used to carry torpedoes on night patrol.
On the night of 24–25 October 1944 she was on patrol in Surigao Strait among the motor torpedo boats gathered there. Thirty-nine boats made up that patrol, and PT-331 was one of them.
That patrol is her place in the Battle of Surigao Strait, dated 25 October 1944. She is recorded in the motor torpedo boat patrol as the battle was fought.
The night of 24–25 October 1944 in Surigao Strait is the service tied to this hull. She was one of the thirty-nine boats on the strait, present for the Battle of Surigao Strait.