Following amphibious warfare training out of San Diego, Niagara sailed 26 May 1945 with cargo and 887 Marines, whom she landed at Pearl Harbor 1 June.

She then set course for Cebu to embark the Army's 164th Regimental Combat Team, sailed 1 September, arrived Yokohama the 8th, and landed her occupation troops.

She departed Bikini 21 August for and towed the battleship USS Pennsylvania (BB-38) to Kwajalein for tests, and Pearl Harbor en route to San Francisco, arriving 16 September.

Niagara remained on the west coast until she departed San Diego 7 November, steaming via the Panama Canal to Hampton Roads, Virginia.

After serving to test the effects of special conventional explosives in the Chesapeake Bay, Niagara was sold for scrapping on 5 February 1950 to the Northern Metals Company of Philadelphia, Pennsylvania.