"Cowell" returned to Majuro 22 March 1944 and rejoined TF 58 for the strikes on Palau, Yap and Ulithi of 30 March to 1 April; the invasion of Hollandia from 21 to 23 April; and the raids on Truk, Satawan and Ponape of 29 April to 1 May. After the air attacks on Marcus Island and Wake Island from 19 to 23 May, "Cowell" continued to screen the carriers during the Marianas operation. She sortied from her base at Majuro from 6 June to 14 July for strikes on Guam and Rota, raids to neutralize Japanese bases in the Bonins, and to give protective antiaircraft cover for the carriers in the Battle of the Philippine Sea on 19 and 20 June.