Schwartz represents Canada internationally. His first experience with Hockey Canada came while representing Team West at the World Junior A Challenge in 2008, capturing a silver medal and the World Under-17 Hockey Challenge in 2009, with a fourth-place finish. Schwartz helped Canada capture a gold medal at the 2009 Ivan Hlinka Memorial Tournament. Schwartz scored a goal and added an assist in the gold medal game. He was selected to represent Canada at the 2011 World Junior Championships. In his second game of the tournament, against the Czech Republic, Schwartz suffered a fractured ankle and was sidelined for the rest of the tournament. He was selected the next year to Team Canada for the 2012 World Junior Championships in Edmonton and Calgary and named team captain. Playing Russia in the semifinal, Schwartz recorded a goal and five shots to be named Canada's player of the game in a 6–5 losing effort. He finished the tournament with five points (two goals and three assists) over six games, as Canada won the bronze medal over Finland.