David Lewis (1901-1980) was a Russian-born Canadian lawyer and politician. He was national secretary of the Cooperative Commonwealth Federation from 1936 to 1950, and one of the key architects of the New Democratic Party in 1961. He was elected as a Member of Parliament from 1962 to 1963 and 1965 to 1974, and served as leader of the NDP from 1971 to 1975, during which time the party held the balance of power in the Liberal minority government of 1972 to 1974.

He was the father of Stephen Lewis, a former Ontario New Democratic Party leader who is now the United Nations Special Envoy for HIV/AIDS in Africa.