A referendum on electoral redistributions in South Australia was held on 9 February 1991.

The proposal put to voters would require the South Australian Electoral Districts Boundaries Commission to redistribute the electoral boundaries following every election, and to consider a broader range of criteria when reviewing boundaries: specifically, "to draw the boundaries in such a way that the party with the majority of (the two-party) vote would also win the majority of seats and so be able to form government".

The proposals were accepted by a wide margin.

[1] As of 2024, this is the most recent South Australian state referendum.