At the end of May, the "White Plains" steamed out of port in company with units of the Task Forces assembled to invade the Mariana Islands. The portion of the Fleet containing the "White Plains" sortied from Eniwetok Atoll, and during the voyage from there to the Marianas, her aircraft provided antisubmarine warfare patrols and part of the combat air patrol. During the assault on Saipan, her planes continued to cover the Fleet against submarine and air attack, strafed the beaches, and spotted shellfire for gunfire support ships. They helped repulse at least three major enemy air attacks. On 17 June, while helping to fight off those raids, her antiaircraft gunners earned their first definite kill. Later, VC-4 Avengers successfully torpedoed an enemy transport during a sweep of the island of Rota.