 In June 2017, Barrett was one of three uncapped backs named in the All Blacks' 33-man squad for the Pasifika Challenge against Samoa and the three-test series against the touring British and Irish Lions 2017 team, along with brothers Beauden and Scott.In what was brother Beauden's 50th test, Barrett made his international debut in the 78-0 against Samoa on 16 June 2017, replacing All Blacks captain Ben Smith in the 63rd minute.Barrett was one of two debutants that day, with Hurricanes team-mate Vaea Fifita replacing veteran loose forward Jerome Kaino off the bench.