Louis-Joseph-Lucien Cardin, PC QC (March 1, 1919 – June 13, 1988) was a Canadian lawyer, judge, and politician.

The Honourable Lucien Cardin PC QC
Cardin, c. 1966
Minister of Justice Attorney General of Canada
In office July 7, 1965 – April 3 1967
Prime Minister	Lester B. Pearson
Preceded by	George McIlraith (Acting)
Succeeded by	Pierre Trudeau
Member of Parliament for Richelieu—Verchères
In office October 6, 1952 – April 3, 1967
Preceded by	Gérard Cournoyer
Succeeded by	Jacques Tremblay
Personal details
Born	Louis-Joseph-Lucien Cardin (1919-03-01)March 1, 1919 Providence, Rhode Island, U.S.
Died	June 13, 1988(1988-06-13) (aged 69)
Political party	Liberal
Military service
Allegiance	Canada
Branch/service	Royal Canadian Navy
Years of service	1941–1945
Rank	Lieutenant-Commander

Born in Providence, Rhode Island, the son of Octave Cardin and Eldora Pagé, he studied at Loyola College and at the Université de Montréal. During World War II, he served in the Royal Canadian Navy and was discharged with the rank of Lieutenant Commander. He was called to the Quebec Bar in 1950.

In a 1952 by-election, he was elected to the House of Commons of Canada as a Liberal in the Quebec riding of Richelieu—Verchères. He was re-elected in 1953, 1957, 1958, 1962, 1963, and 1965.

From 1956 to 1957, he was the Parliamentary Assistant to the Secretary of State for External Affairs. From 1963 to 1965, he was the Associate Minister of National Defence. In 1965, he was the Minister of Public Works. From 1965 to 1967, he was the Minister of Justice and Attorney General of Canada.

Cardin was the first Canadian politician to bring the public's attention to the Munsinger affair. During taunts by Conservative MPs in the House of Commons in March 1966, Cardin shouted out across the floor of the House, "What about Monsignor?" Although he got the name wrong and later insisted that he thought Gerda Munsinger had died, the media brought attention to the issue, and there was a federal inquiry that caught the public's attention for its implications to national security during the Cold War.

He was appointed Assistant Chairman of the Tax Review Board in April 1972 and Chairman of the Tax Review Board in 1975. He was appointed Chief Judge of the Tax Court of Canada on July 18, 1983.