The South African 1st Infantry Brigade was an infantry brigade of the army of the Union of South Africa during World Wars I and II. During World War I, the Brigade served as a British formation in Egypt and on the Western Front, most famously the battle of Delville Wood. It was reactivated at the start of the Second World War as a South African formation and served in East Africa and the Western Desert. The Brigade was finally disbanded on 1 January 1943.