Ballentine served as the first commanding officer of the fleet carrier USS "Bunker Hill" from 25 May 1943 to 5 February 1944. He was awarded the Silver Star for his actions in November 1943 during the Gilbert Islands campaign. Promoted to rear admiral, Ballentine next served as chief of staff for Naval Air Force Pacific. He later assumed command of Carrier Division SEVEN on 27 June 1945. Based aboard operating near Japan as part of Task Force 38, Ballentine continued in this role until 19 August 1945.