After training exercises in the New Hebrides in January 1944, Columbia helped spearhead the attack and occupation of Nissan, one of the Green Islands from 13 to 18 February.
Columbia sortied from Port Purvis on 6 September with the covering force for the landings in the Palaus, and remained off Peleliu to provide gunfire support to forces ashore and protection to assault shipping until her return to Manus on 28 September.