The Friends' Ambulance Unit (FAU) was a volunteer ambulance service, founded by individual members of the British Religious Society of Friends (Quakers), in line with their Peace Testimony. The FAU operated from 1914–1919, 1939–1946 and 1946–1959 in 25 different countries around the world. It was independent of the Quakers' organisation and chiefly staffed by registered conscientious objectors.