Pretoria was founded in 1855 by Marthinus Pretorius, a leader of the Voortrekkers, who named it after his father Andries Pretorius and chose a spot on the banks of the Apies rivier (Afrikaans for "Monkeys river") to be the new capital of the South African Republic (Dutch: Zuid Afrikaansche Republiek; ZAR). The elder Pretorius had become a national hero of the Voortrekkers after his victory over Dingane and the Zulus in the Battle of Blood River in 1838. The elder Pretorius also negotiated the Sand River Convention (1852), in which the United Kingdom acknowledged the independence of the Transvaal. It became the capital of the South African Republic on 1 May 1860.

The founding of Pretoria as the capital of the South African Republic can be seen as marking the end of the Boers' settlement movements of the Great Trek.

Pretoria is situated approximately 56 km (35 mi) north-northeast of Johannesburg in the northeast of South Africa, in a transitional belt between the plateau of the Highveld to the south and the lower-lying Bushveld to the north. It lies at an altitude of about 1,339 m (4,393 ft) above sea level, in a warm, sheltered, fertile valley, surrounded by the hills of the Magaliesberg range.