Lachlan Chisholm Wilson CB CMG (11 July 1871 – 7 April 1947 ) was a soldier and lawyer from Queensland, Australia. He was brigadier-general in the Australian Light Horse in World War I.
Lachlan Chisholm Wilson was born on 11 July 1871 at the Logan River, Queensland, Australia, the son of a farmer. He attended Coorparoo State School and Brisbane Grammar School. He initially worked in the Queensland Lands Department, but then chose to study law, and was admitted to the Supreme Court of Queensland in 1895, and started practice as a solicitor in Townsville.
Wilson fought in the South African War as a corporal in the 2nd Queensland Mounted Infantry Contingent, serving in the advance to Johannesburg and Pretoria, the Battle of Diamond Hill and other actions. Commissioned in the 15th Light Horse Regiment in 1904, he trained with other future leaders of the Light Horse under Lieutenant-Colonel (Sir) Harry Chauvel. Promoted major in 1911, Wilson was second-in-command of the Moreton Regiment after his return to Brisbane. There he entered into a partnership with E. K. Tully to form one of Queensland's leading law firms.
Following the outbreak of World War I, Wilson joined the Australian Imperial Force as a major on 30 September 1914. In November he transferred from the 7th Light Horse Regiment to the 5th Light Horse Regiment, of which he became second-in-command. He landed at Gallipoli in May 1915 and took charge of the 5th on 1 August after its commanding officer was killed. A lieutenant-colonel from that date, Wilson mounted a successful raid against Bird Trenches near Gaba Tepe on 23 August; in November, after repulsing a Turkish attack, he seized positions known thereafter as Wilson's Lookout.