South Australian state election, 1921

State elections were held in South Australia on 9 April 1921. All 46 seats in the South Australian House of Assembly were up for election. The incumbent Liberal Union government led by Premier of South Australia Henry Barwell defeated the opposition Australian Labor Party led by Leader of the Opposition John Gunn. Each district elected multiple members, with voters casting multiple votes.

The coalition between the National Party and the Liberal Union had collapsed in 1920, and the former contested the 1921 election, in conjunction with a section of dissident Liberals, as the short-lived Progressive Country Party.