Seguin competed for Canada at the 2009 Ivan Hlinka Memorial Tournament in the Czech Republic, where he led the team in scoring with ten points in four games as Canada won the gold medal. He then attended Hockey Canada's selection camp for the 2010 World Junior Ice Hockey Championships in December 2009, but did not make the team. Previously, he won gold with Team Ontario in the 2009 World U-17 Hockey Challenge in Port Alberni, British Columbia, and finished second in tournament scoring with 11 points in six games. Seguin attended Canada's World Junior selection camp in Regina, Saskatchewan, for the World Junior Championships, the under-20 level, but again failed to make the team. In 2015, he was a member of Canada's gold medal-winning team at the World Hockey Championships.