Lanier served as an attack transport of the Haskell class, APA-125. California Shipbuilding launched her at Wilmington on 29 August 1944. She was commissioned on 22 December 1944.
Her operation was a reinforcement of Okinawa. Between 2 and 6 May 1945 she crossed from Saipan to the island. Aboard were 1,442 troops and the equipment that belonged to them, a full lift for a beach already in the campaign's second month.
She landed those men as reinforcements. The boats took them in, and the equipment followed. When the beach had taken the load, the ship turned to the other half of an attack transport's work and brought casualties off.
Sixty-six battle casualties came aboard. She was decommissioned on 5 March 1946, and one battle star marks the Okinawa reinforcement.