In 2005 Stewart was again selected to play for Canada in the World Junior Championships in Grand Forks, North Dakota. Unlike in previous years, Stewart struggled at this tournament, and in the second game he was relegated to 13th forward. An injury to teammate Jeremy Colliton allowed Stewart to play in the following game, in which he scored two goals, contributing to a 9–0 defeat of the German team. Once more, Canada had an undefeated run to the final, where they faced Russia. In the final Stewart scored the fifth goal in a 6–1 win for Canada, earning him his third international gold medal.