No. 8 Squadron was formed during World War I, being raised as a flying training squadron of the Australian Flying Corps at Yatesbury, England, during on 25 October 1917. The squadron received its first aircraft in January 1918 and trained replacement pilots for No. 4 Squadron until being disbanded following the conclusion of the war on 30 April 1919. The squadron's first commanding officer was Major G.A.C. Cowper; it was initially designated as No. 33 (Australian) (Training) Squadron, Royal Flying Corps.
During World War II, No. 8 Squadron was re-formed as a bomber-reconnaissance unit at RAAF Station Canberra, which was later retitled as RAAF Station Fairbairn, Canberra, on 11 September 1939.