He was part of the Canadian squad that competed at the
2015 Pan American Games and won a silver medal. In 2016, he was named to Canada's Olympic team. He was selected for the
2018 World Cup, where he played all four games. In June 2019, he was selected in the Canada squad for the
2019 Pan American Games. They won the silver medal as they lost 5–2 to
Argentina in the final. In June 2021, Johnston was named to
Canada's 2020 Summer Olympics team. He was the top goalscorer at the
2022 Men's Pan American Cup with ten goals as Canada won the bronze medal. ==References==