As an adult, Marchand was one of three members of the Bruins to attend the 2016 IIHF World Championship in Russia: he represented Canada, while Pastrňák represented the Czech Republic and Providence Bruins skater Frank Vatrano played for Team USA. Canada took first place in the tournament after defeating the previously-undefeated Finnish team in a gold medal match that saw Marchand fight Leo Komarov of the Toronto Maple Leafs. On May 27, 2016, Marchand was named to Team Canada's roster for the 2016 World Cup of Hockey, joined by his teammate Patrice Bergeron. During the tournament, he played on a line with Bergeron and Sidney Crosby of the Penguins, combining for 25 points in six games. Marchand led the tournament with five goals and three assists. His short-handed goal against Team Europe in the World Cup finals clinched a gold medal for Canada, something that Marchand and his teammates hoped would establish the skater as a strong player rather than a pest.