The Transvaal Colony was the name used to refer to the Transvaal region during the period of direct British rule and military occupation between the end of the Second Boer War in 1902 when the South African Republic was dissolved, and the establishment of the Union of South Africa in 1910. The borders of the Transvaal Colony were larger than the defeated South African Republic. In 1910 the entire territory became the Transvaal Province of the Union of South Africa.

The Second Boer War, also known as the Boer War, Anglo–Boer War, or South African War, was a conflict fought between the British Empire and the two Boer republics over the Empire's influence in Southern Africa.