The office of premier of South Australia was established upon the commencement of responsible government with the passage of the Constitution Act 1856.

The role was based upon that of the prime minister of the United Kingdom, with the premier requiring the support of a majority of the members of the lower house to remain head of government.

For the early years of responsible government, the office was held in conjuction with that of Chief Secretary of South Australia, a role that had existed since colonsiation, but by the 1890's, this was no longer a convention.

If for any reason the incumbent premier lost sufficient support through a successful motion of no confidence at any time on the floor of the house, he would tender his resignation to the governor of South Australia, which would result in another member deemed to have the support of the House of Assembly being sworn in by the governor as the next premier.

Labor formed South Australia's first majority government after winning the 1910 state election, triggering the merger.