William Kashtan (27 June 1909[1] – 1993) was the general secretary of the Communist Party of Canada for 23 years beginning in January 1965, several months following the death of Leslie Morris, until his retirement in 1988.

In 1970, Kashtan spoke out against the Front de libération du Québec (FLQ) group in Quebec, describing it as a terrorist organization and claiming that its methods were not consistent with genuine revolutionary behaviour.

In the early 1990s, following the dissolution of the Soviet Union, Hewison and his supporters attempted to move the Communist Party away from Marxism-Leninism and towards social democracy in light of the failure of Soviet-style Communism.

Kashtan came out of retirement to fight the changes, along with future Party leader and then member of the Central Executive, Elizabeth Rowley.

And continuing interference in the affairs of Afghanistan by Cpina [recte China], Pakistan, as well as the CIA, is an external reason mentioned by Kashtan.