The plurality voting system is a single-winner voting system often used to elect executive officers or to elect members of a legislative assembly which is based on single-member constituencies.

The most common system, used in Canada, India, the UK, and the USA, is first past the post or winner-takes-all, a voting system in which a single winner is chosen in a given constituency by having more votes than any other individual representative.

In some countries such as France a similar system is used, but there are two rounds: the "two-ballot" or "runoff election" plurality system. The two highest-voted candidates of the first round compete in a two-candidate second round or all candidates above a certain threshold in the first round compete in a two-, three- or four-candidate second round. If one candidate has a majority of votes in the first round, there is no second round.

In political science, the use of the plurality voting system alongside multiple, single-winner constituencies to elect a multi-member body is often referred to as single-member district plurality or SMDP. Plurality voting is also variously referred to as winner-takes-all or relative/simple majority voting; however, these terms can also refer to elections for multiple winners in a particular constituency using bloc voting.

The famous works of Arend Lijphart use the term "majoritarian" systems, where a plurality voting system is one of the defining variables . These terms are thus sometimes used almost synonymously.