An interim leader, in Canadian politics, is a party leader who is appointed by the party's legislative caucus to temporarily lead the party, when there is a gap between the resignation or death of a party leader and the election of his or her formal successor.

A Canadian party leader is always selected by the party members, either through a "one member one vote" (OMOV) system or through a delegate selection process. Usually a party leader retains the leadership until his or her successor takes over; however, in some situations this is not possible. This may be because the leader passes away (eg. Wilfrid Laurier), or because a leader is forced to resign due to controversy or scandal before a convention can be organized (eg. Glen Clark), or because a leader is forced to recontest his or her leadership (eg. Joe Clark, Stockwell Day), or because a new party is incorporated from existing party caucuses (eg. Canadian Alliance, Conservative Party of Canada).

When this happens, an interim leader is appointed by the party's caucus. By convention, an interim leader must be a caucus member who is not standing as a candidate in the official leadership race, so that he or she does not gain unfair advantage in the leadership contest.

Interim leaders in Canadian politics have included: