William Stewart played for Dundee Boys before joining Newton Heath (Manchester United) when only 17 years old. Over the next three seasons Stewart played in 62 matches for Newton Heath. In 1892-93 the club were accepted into the Football League First Division. Stewart played another 76 games before joining Luton Town in the Southern League. In his first season he scored four goals from wing half. He also played for Millwall before returning to Luton in 1899. Stewart joined the Thames Iron Works half-way through the 1899-1900 season. Stewart played in the final 17 league games. At the end of the season Stewart returned to Dundee.