David Wallace Caldwell was born in South Australia during 1892 to David and Margaret Caldwell. A carpenter before the First World War, Caldwell enlisted on the 26 January 1915 and was assigned to the Infantry Base Depot. He was promoted to sergeant and departed Adelaid with the 27th Infantry battalion in Adelaide aboard HMAT Geelong on 31 January 1915.

Caldwell served with the 27th Infantry Battalion in Gallipoli and France until July 1916 where he was transferred to the 9th Cadet Battalion in England. On completing his studies at the School of Instruction, he was discharged from Gailes Ayrshire on the 10 November 1916 and told to report to Perham Downs. It was here that he re-joined the 27th Infantry Battalion. David Caldwell was killed in action on 2 March 1917 whilst participating in an attack on German position at night and is buried at Warlencourt British Cemetery, France.