List of Manitoba by-elections

The list of Manitoba by-elections includes every provincial by-election held in the Canadian province of Manitoba. By-elections occur whenever there is a vacancy in the Legislative Assembly, although an imminent general election may allow the vacancy to remain until the dissolution of parliament.

Causes
A by-election occurs whenever there is a vacancy in the Manitoba Legislature. Vacancies can occur for the following reasons:


 * Death of a member
 * Resignation of a member
 * Voided results
 * Expulsion from the legislature
 * Ineligibility to sit
 * Appointment to the Legislative Council, the appointed upper house of Manitoba, which was abolished in 1876.
 * Appointment to the Cabinet.
 * Incumbent members were required to recontest their seats upon being appointed to Cabinet; these Ministerial by-elections were almost always uncontested. This requirement was first enacted in 1872 and took effect at the 1874 general election. The requirement was clarified in 1875 to exempt ministers who resigned their offices and, within a month, accepted a new office. In 1924, members from Winnipeg—a 10-member constituency at the time—were exempted from having to seek re-election. In 1927, the remaining members were exempted from seeking reelection if they were appointed within one year of a general election. The requirement was abolished completely in 1937.

10th–19th Legislatures (1899–1936)
† Won by acclamation