Returning to combat in mid-1943, "Portland" saw action in many of the major engagements of the Pacific War, conducting shore bombardments in support of campaigns at the Aleutian Islands, Gilbert and Marshall Islands, Mariana Islands, and New Guinea. She was involved in the October 1944 Battle of Leyte Gulf, engaging Japanese ships in the decisive Battle of Surigao Strait. She then conducted shore bombardments at Lingayen Gulf and Corregidor Island, and in 1945 supported landings during the Battle of Okinawa until the end of the war.