The Spartacist League is the name of several Trotskyist groups, which are sections of the International Communist League (Fourth Internationalist):
Spartacist League (US) Spartacist League of Britain Spartacist League of Australia Spartacist League of Israel Spartacist League of Sri Lanka
Spartacus League is the name of: The original Spartacus League (Spartakusbund, 1914–1919), a communist organisation in post-World War I Germany well known for its ties to the revolutionary Rosa Luxemburg Spartacus League of Left Communist Organisations (Spartakusbund linkskommunistischer Organisationen, 1926–1927), a league of left communist organisations in Germany. Spartacus League (1974) (Spartacusbund, 1974–1981/82), a Trotskyist group in Germany Spartacus League UK (1970–1972), a youth group linked with the International Marxist Group Spartacus League (Greece)