League for Socialist Action (Canada)

League for Socialist Action
LeaderMaurice Spector
Jack Macdonald
Earle Birney
Ross Dowson
John Riddell
FounderMaurice Spector
Jack Macdonald
Founded1934 (1934)
Dissolved1977 (1977)
Split fromCommunist Party of Canada (as the Communist League of America and International Left Opposition (Trotskyist) of Canada)
Merged intoRevolutionary Workers League
Youth wingYoung Socialists
IdeologyTrotskyism
International affiliationInternational Left Opposition (1934-1938), Fourth International (1938-1953), International Committee of the Fourth International (1953-1963), United Secretariat of the Fourth International (1963-1977)

The League for Socialist Action (LSA) was the premier Trotskyist organization in Canada for much of the 20th century. Throughout its history the LSA went through many different names and iterations. In chronological order it was known as: the International Left Opposition (Trotskyist) of Canada, the Workers Party of Canada, the Socialist Policy Group, the Socialist Workers League, the Revolutionary Workers Party, The Club, the Socialist Education League, and the League for Socialist Action.