Reitan turned professional after he earned the 26th card at the
2018 European Tour Qualifying School, the only amateur to earn a card. In his rookie season on the European Tour, his best finish was a tie for fifth at the
ISPS Handa World Super 6 Perth in Australia, where he shared the lead after round one. He ended the season 141st in the rankings, retaining conditional status. In April 2025, he was runner-up at the
Hainan Classic in China, three strokes behind
Marco Penge. In May, he claimed his first European Tour title, at the
Soudal Open. Starting the final round nine strokes off the lead, Reitan shot a course-record 62 and posted 13-under for the tournament to ultimately enter a three-man playoff. Reitan birdied the second extra hole to defeat
Darius van Driel and 54-hole leader
Ewen Ferguson. After another runner-up finish at the
Austrian Alpine Open, following a 60 in the final round, Reitan rose into the top-100 of the
Official World Golf Rankings for the first time. Reitan ended the season at 8th in the
Race to Dubai rankings and earned playing status for the
2026 PGA Tour season. At the
Nedbank Golf Challenge in December 2025, Reitan opened with a 9-under 63 to take the first-round lead. He held a five-stroke lead after 54 holes and shot a 72 in the final round to complete a
wire-to-wire victory, finishing one stroke ahead of
Dan Bradbury and
Jayden Schaper. ==Amateur wins==