Single-member district

A single-member district is an electoral district represented by a single officeholder. It contrasts with a multi-member district, which is represented by multiple officeholders. Single-member districts are also sometimes called single-winner voting, winner-takes-all, or single-member constituencies.

A number of electoral systems use single-member districts, including plurality voting (first-past-the-post), two-round systems, instant-runoff voting (IRV), approval voting, range voting, Borda count, and Condorcet methods (such as the Minimax Condorcet, Schulze method, and Ranked Pairs). Of these, plurality and runoff voting are the most common.

In some countries, such as Australia and India, members of the lower house of parliament are elected from single-member districts; and members of the upper house are elected from multi-member districts. In some other countries like Singapore, members of parliament can be elected from both single-member districts as well as multi-member districts.