Hemský was a member of the bronze medal-winning Czech team at the 2006 Winter Olympics. He missed the 2010 Winter Olympics, but was selected for 2014 Olympic ice hockey tournament at Sochi in 2014 and became the highest scorer for the Czech team during the 2014 games, with three goals and four points. Hemský has also represented his country in three International Ice Hockey Federation (IIHF) world ice hockey tournaments, winning a gold medal with the team in 2005 and bronze in 2012. He made his first appearance in a Czech uniform for the 2002 World Junior Ice Hockey Championships.