Donald Law Patrick Cameron was born at Balranald, New South Wales in 1897. He was living in Mosman and working as a motorboat driver when he enlisted on 8 February 1917. Although Cameron had spent two years with the Citizens Naval Reserve, he joined the Imperial Camel Corps and departed Sydney aboard HMAS Port Sydney on 9 May 1917.

After arriving in Egypt in June, Cameron became an acting corporal in the Camel Reserve Company, and then joined the 4th Battalion, Imperial Camel Corps in August 1917 as a trooper. He served in Palestine throughout 1917 and in mid-1918 joined the 1st Light Horse Regiment, then serving in Jordan. Cameron's stay with the 1st Light Horse Regiment was short-lived as he soon transferred to the Mobile Veterinary Section and then fell sick in September 1918, spending three months recovering from fever. After recuperating, Cameron served out the rest of the war with the Australian Base Post Office in Egypt, finally returning to Australia on 14 March 1919. Donald Cameron also enlisted in the Second World War as a warrant officer with the 202 Australian Camp Hospital.