The Kellock–Taschereau Commission (officially the Royal Commission to Investigate the Facts Relating to and the Circumstances Surrounding the Communication, by Public Officials and Other Persons in Positions of Trust of Secret and Confidential Information to Agents of a Foreign Power) was a royal commission appointed by Prime Minister William Lyon Mackenzie King on behalf of the Government of Canada under Order in Council PC 411 on 5 February 1946 to investigate the "Gouzenko Affair", allegations set forward by Soviet defector Igor Gouzenko that a spy ring of Canadian Communists was handing over secret information to the Soviet Union. Notable among the thirteen accused of passing over secrets were Fred Rose, the Labor-Progressive Party Member of Parliament for Cartier, and Sam Carr, a senior organizer of the Labor-Progressive Party. The commission was headed by two judges of the Supreme Court of Canada, Justice Robert Taschereau and Justice Roy Kellock. Counsel included President of the Canadian Bar Association E.K. Williams, D.W. Mundell, Gérald Fauteux, and John Robert Cartwright.
The impact of the Kellock–Taschereau Commission was far-reaching. In response to alleged abuses of procedure against the accused a group formed to advocate on their behalf. The Emergency Committee for Civil Rights had many prominent members, including executive members C.B. Macpherson, Leopold Infeld, and A.Y. Jackson. They asserted that the Commission endangered the "basic rights of Canadians" and did "violence to the rights of free men." In an advertisement in the Toronto Star, they compared the Kellock–Taschereau Commission to the trial of Lt.-Col. John Lilburne during the English Civil War of 1649, stating "the methods of the Commission are not new. They were used against Englishmen in 1649 and against Canadians in 1946."
This particular Royal Commission was extremely controversial. It represents one of the first trials in North America on Communism and spying. It was also one of the first events of the Cold War and the response was emblematic of the Red Scare. In the Literary Review of Canada, Margaret Atwood listed the report of the Kellock–Taschereau Commission as one of Canada's 100 most important books.