John Stewart, Earl of Mar and Garioch (c. 1456–c. 1479) was the youngest son of James II of Scotland and Mary of Guelders.

James II bestowed the titles of Earl of Mar and Earl of Garioch on his son sometime between 1458 and 1459. In 1479, John was accused of treason and imprisoned at Craigmillar Castle. Shortly thereafter he died in suspicious circumstances, possibly on the orders of his brother James III.