No. 607 (County of Durham) Squadron is an auxiliary squadron of the Royal Air Force. It was formed in 1930 as a bomber unit in the Auxiliary Air Force and changed in 1936 to the fighter role. It fought in that role during the Second World War in Europe and Asia. After the war, in 1946, the squadron reformed as a fighter unit. Awarded the title Royal Auxiliary Air Force by King George in 1947, 607 Sqn was disbanded with all the other flying units of the RAuxAF on 10 March 1957. It reformed on 5 January 2015, as a General Service Support Squadron (GSS).