No. 5 Squadron was a Royal Australian Air Force training, army co-operation and helicopter squadron. The squadron was formed in 1917 as a training unit of the Australian Flying Corps in Britain, readying pilots for service on the Western Front. It subsequently became a naval fleet co-operation squadron, but was later redesignated as No. 9 Squadron RAAF before being re-formed as an army co-operation squadron during World War II. In the mid-1960s, it was re-formed as a helicopter squadron, before being disbanded in December 1989, when it was used to form the Australian Defence Force Helicopter Training School.