After shakedown, "Lanier" departed San Francisco 23 February 1945 and arrived Pearl Harbor 2 March to practice landing operations. Loaded with 1,485 soldiers, she got underway 28 March and steamed in convoy with 11 other transports and five merchantmen for the Volcano Islands. Touching Eniwetok and Saipan, she reached Iwo Jima 20 April and discharged men and cargo. She returned to Saipan 22 to 24 April, took on board equipment and 1,442 troops, then sailed to Okinawa 2 to 6 May. There she landed reinforcements and embarked 66 battle casualties before returning to Saipan 8 to 13 May. On the next day she embarked 254 survivors from "Little" (DD-803), sunk by enemy air attack while on radar picket duty west of Okinawa 3 May.