Alec Campbell enlisted with the AIF as a 16-year-old, lying about his age in order to sign up. Campbell spent a month fighting with the 15th Battalion in the Gallipoli campaign at the end of 1915 before being evacuated to Egypt in December of that year. Campbell was awarded the 1914-15 star, the British War Medal, the Victory Medal and, in later years, the 80th Anniversary Armistice Remembrance Medal.
After being discharged from the army at the age of 18, Campbell worked variously as a jackaroo, carpenter, carriage builder and economist, including a period in Canberra in the early year's of the development of the nation's capital. Campbell's interest in sailing was reflected in his participation in six Sydney to Hobart yacht races.
Campbell was the longest surviving of Australia's Gallipoli veterans.