Stewart Smith (c. 1907 – October 27, 1993) was a long-time leading member of the Communist Party of Canada.

Stewart Smith was one of the main figures in the faction, led by Tim Buck, that took over the party leadership in 1929.

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.

Smith, Ryerson and Morris were made leaders of the party's "operations centre" and effectively led the party until Buck, Carr and Simms returned from exile when the German invasion of the Soviet Union brought the USSR into World War II as an Allied Power.