Andersson was named to Team Sweden for the 2016 IIHF World U18 Championships and helped Sweden win silver by putting up nine points in seven games. He was again named to Team Sweden for the 2017 World Junior Ice Hockey Championships, where he scored three goals. He was named captain to Team Sweden for the 2018 World Junior Ice Hockey Championships, where he helped guide the team to a silver medal, and in a controversial display, threw it into the crowd in frustration. For this action, he was suspended from four games during the 2019 World Junior Ice Hockey Championships.