Major General George Jameson Johnston, CB, CMG, CBE, VD (24 October 1868 – 23 May 1949) was a senior Australian Army officer during the First World War.
In 1899, he volunteered for service in South Africa during the Second Boer War, where in November 1899 he was attached to the British 62nd Battery, Royal Field Artillery with the rank of captain.
In March 1902 he became a temporary lieutenant colonel commanding the 4th Battalion, Australian Commonwealth Horse but the war ended before he reached South Africa.
Johnston was promoted to lieutenant colonel on 24 April 1909 and took command of the Victorian Field Artillery Brigade.
Johnston joined the Australian Imperial Force on 18 August 1914 as a lieutenant colonel commanding the 2nd Field Artillery Brigade.
The rest of the brigade, less the 6th Field Battery, which was diverted to Cape Helles, came ashore the next day, eventually settling on McCay's Hill and MacLagan's Ridge.