Stewart Smith (c. 1907 – October 27, 1993) was a long-time leading member of the Communist Party of Canada. He also served on Toronto City Council for a period in the 1930s and 1940s.
Smith was the son of Reverend A. E. Smith, a social gospel minister who became a leading figure in the Communist Party. Stewart Smith was one of the main figures in the faction, led by Tim Buck, that took over the party leadership in 1929. Smith was elected to the party's Central Committee and continued to serve on it (and the party's Political Bureau) for decades. He supported the expulsion of Trotskyist and Right Opposition factions from the party. In 1934, Smith wrote the pamphlet Socialism and the C.C.F. which promoted the Communist Party's view that the newly formed democratic socialist Co-operative Commonwealth Federation was an obstacle to socialism which served as a buffer between the working class and the capitalist class that needed to be defeated.
In 1935, Smith led the Canadian delegation to the world congress of the Communist International held in Moscow. When he returned, he echoed the Comintern's new line rejecting the previous Third Period sectarianism of the party and advocating class unity and ultimately Popular Frontism in its stead resulting in the dissolution of the party's red union, the Workers' Unity League into the American Federation of Labour and Congress of Industrial Organizations.