Brown played Gaelic football for County Derry before the Greater Western Sydney Giants' Irish scouting program found him in 2017, and in 2018 he became the first player to join the club's AFL program straight from Ireland. He debuted in round 21 of 2021 with two majors against Geelong, and set career highs in 2025 with 22 matches and 25 majors. He has played 82 AFL games and kicked 89 goals.