The son of former North Melbourne player and chairman Ben Buckley, Jack joined Greater Western Sydney as a category B rookie forward and debuted on a wing in round 17 of 2020. An ACL injury then cost him more than 600 days before he returned in 2023 to win the club's Coaches Award and settle in as a one-on-one defender alongside Sam Taylor. He took the Best Finals Player award in 2024 and has played 94 AFL games.