A full Chilean international with over 130 caps since 2007, Medel has represented the nation at two FIFA World Cups, five Copa América tournaments, and one edition of the FIFA Confederations Cup. He was part of the squad that won the 2015 Copa América (where he was named in the Team of the tournament) and the Copa América Centenario. He was also included in the squads that finished fourth at the 2019 Copa América, and were runners-up at the 2017 Confederations Cup.