The South Australia Act 1834, or Foundation Act 1834 and also known as the South Australian Colonization Act, was an Act of the Parliament of the United Kingdom which provided for the settlement of a province or multiple provinces on the lands between 132 degrees east and 141 degrees of east longitude, and between the Southern Ocean, and 26 degrees south latitude, including the islands adjacent to the coastline.

It also set up a London-based Board of the South Australian Colonization Commission allowing for three or more appointed commissioners (board members), known as the Colonization Commissioners for South Australia or, later, Colonisation Commissioners, to oversee the sale and leasing of land in South Australia to British subjects. This Board was to be represented in the new colony by a Resident Commissioner, Surveyor-General, an Emigration Agent and various other colonial officers.

In 1838, an amendment, which was referred to as the South Australia Government Act 1838, provided formal instructions for the establishment of the colony and, significantly, included acknowledgement of the rights of the Indigenous peoples in the area to be proclaimed as a colony.

The Act was repealed by the South Australia Act 1842, which instituted a different form of government for the colony, with the Governor presiding over an appointed Legislative Council, and established a commission to lay the foundations of a democratic form of government. The Commission was abolished in 1842 and its functions continued from early 1843 by the Colonial Land and Emigration Commission, which had been established by a Commission from Queen Victoria on 14 January 1840.