After reaching the final stage of the
European Tour Qualifying School in 2017 but failing to qualify, Brown played a limited schedule on the
Challenge Tour in 2018 but made only two cuts in 13 events. From 2019 to 2021, Brown played on the
PGA EuroPro Tour. In 2021, he tied for second in the season-ending event and finished fourth in the Order of Merit, earning a return to the Challenge Tour. He finished 30th in the
2022 Challenge Tour rankings, highlighted by a runner-up finish at the
Hopps Open de Provence in October. In November, Brown finished third at the
European Tour Qualifying School to claim a
European Tour card for the
2023 season. In August 2023, Brown claimed his first win on the European Tour at the
ISPS Handa World Invitational in Northern Ireland. He won
wire-to-wire, five shots ahead of
Alex Fitzpatrick. In July 2024, he made his
major championship debut at the
2024 Open Championship after earning a place in the field through final qualifying, and had the lead after the first round after a bogey-free 65. In July 2025, Brown won the
BMW International Open by two shots over
Jordan Smith. He earned a
PGA Tour card following the 2025 DP World Tour season. Brown had originally finished 11th among those not otherwise exempt, with the top 10 earning PGA Tour cards. However, he earned the 10th spot after
Laurie Canter opted instead to rejoin LIV Golf. ==Amateur wins==