Lieutenant-General Sir Jacob Louis van Deventer KCB CMG DTD (18 July 1874 – 17 August 1922) was a South African military commander.
He began his military career in the Transvaal republican forces in Pretoria on 21 February 1896, and fought in the Anglo-Boer War (1899-1902).
He returned to military service in World War I, and commanded a Union Defence Forces formation in the South West Africa Campaign (1914-1915).
In the German East Africa Campaign (1916-1918), he commanded a South African Overseas Expeditionary Force mounted brigade, then a division, and finally (1917-1918) all the British imperial forces in the region (though, allegedly, he could hardly speak English).
[3] In 1922, he commanded a mounted brigade in operations to crush the Rand Revolt on the Witwatersrand.