Demers first played for Team Canada during the NHL Lockout at the 2013 Spengler Cup. Demers was added to Team Canada for his first IIHF sanctioned tournament at the 2017 World Championships in Germany/France. In 10 games, Demers went scoreless as Canada suffered a 2-1 shootout defeat in the final against Sweden on May 21, 2017, to finish with the Silver Medal.