Grace Holmes Carlson (November 13, 1906 – July 7, 1992) was an American Marxist politician. Born in St. Paul, Minnesota, Carlson was raised in local Catholic schools. As a leading member of the Socialist Workers Party she was imprisoned in 1941 under the Smith Act together with many other SWP leaders for opposing the US involvement in World War II. After her 16-month prison sentence, she became an activist for better conditions for women prisoners.
Grace Carlson was the Socialist Workers Party candidate for Senate in Minnesota in 1940, receiving almost 9,000 votes. She ran as the Socialist Workers Party vice presidential candidate in 1948 with Farrell Dobbs and ran again as a U.S. House of Reperesentatives candidate for Minnesota's 5th district 1950.
She had been a professor of psychology at the University of Minnesota.
She left the SWP in 1952 citing conflict with her Catholic beliefs. James P. Cannon, the central leader of the SWP famously penning the article "How We Won Grace Carlson and How We Lost Her" following her resignation which focused on the extreme right wing pressures of the McCarthy period as the material basis for Carlson's departure.