Brown was drafted to Collingwood with the 50th pick of the 2017 AFL draft, which was Collingwood's third and final pick, under the father–son rule after Port Adelaide put in a bid for him.[5] He has been compared to his father, Gavin Brown, with Eastern Ranges coach, Darren Bewick saying "he's a shy boy, very introverted in the way he goes about his business, but like his old man, he has a lot of ability."[6] Brown got his first taste of senior football when he played in a pre-season match against Fremantle in the 2019 JLT Community Series.[7] Despite not playing a senior game in his first two years at the club, he showed enough in the reserves to earn a contract extension until the end of 2020.[8] In 2019, he was also often named as an emergency for the senior squad.[9] He made his AFL debut in Collingwood's victory over Western Bulldogs in the opening round of the 2020 season at Marvel Stadium. Due to the COVID-19 pandemic, his debut was without a crowd.[10][11]
After a 2022 AFL season in which both Brown and his brother Callum failed to establish themselves in new coach Craig McRae's best 22, both Brown brothers were delisted at the conclusion of that season.[12]
^The 2020 season was played with 17 home-and-away matches per team (down from 22) and 16-minute quarters with time on (down from 20-minute quarters with time on) due to the impact of the COVID-19 pandemic.