A by-election is a special election held to fill a political office that has become vacant between general elections. Usually this occurs when the incumbent has died or resigned, but it may also occur when the incumbent becomes ineligible to continue in office, for example because of a recall or a criminal conviction sufficiently serious.

The vast majority of by-elections are unimportant and voter turnouts are seldom comparable with general elections.

Community content is available under CC-BY-SA unless otherwise noted.