Jack Anderson Clark was born in Cessnock, New South Wales in the late 1880s. Jack was a shoemaker by trade, having travelled to Scotland to complete his apprenticeship before returning to Cessnock. An accomplished player, Jack won back-to-back Ellis Cups in 1911 and 1912, and represented Newcastle on two occasions in 1911 and 1913.
Clark enlisted on 3 May 1915, and served as a driver for the Field Artillery Brigade.
Returning after the war in early 1919, Jack continued his football career, playing for Cessnock.