The squadron, equipped with Hurricanes, was moved in March to RAF Speke, Liverpool, where it made frequent patrols over naval convoys as part of No.
In July it was moved to RAF Northolt, West London, re-equipped with Spitfires and began to conduct offensive fighter sweeps over occupied Europe.
During two operations over France, on 9 August, the squadron achieved its first aircraft claims—two Bf 109s destroyed, three probables and three damaged.
The squadron formed part of southern England's defence against the V-1 flying bombs and served in the Battle of Normandy.
After the war, 315 Squadron remained part of RAF Fighter Command until it was disbanded on 14 January 1947.