former political party in South Africa, founded by Louis Botha (Botha, Louis) in conjunction with the creation of the Union of South Africa in 1910. It strove to conciliate British South Africans and Boers within the framework of the British Commonwealth. The party was formed from the coalition that won control of the government in the elections of 1910, making Botha the first prime minister of the Union. Before long the party lost J.B.M. Hertzog, a member of Botha's first Cabinet, who in 1914 founded the opposition National Party to express a more stridently Afrikaner perspective. The South African Party, a strong supporter of the Allies in World War I, stayed in power for 14 years. Jan Smuts (Smuts, Jan) became prime minister after Botha died in 1919. The party, led by Smuts, was strengthened in 1920–21 with the addition of members from the defunct Unionist Party, the strongly pro-British party of Cecil Rhodes and Leander Jameson.

A crisis in the mining industry, with resultant discontent among white labourers, contributed to the South African Party's defeat in the elections of 1924. The victory went to the National Party; Hertzog became prime minister. The South African Party remained in opposition until 1933, when it formed a coalition with and then merged with the National Party—in difficulties because of economic depression—to form the United Party (in full, the United South African National Party).