Ryan Dylan Merlen (born 11 May 2002) is a French professional football player who plays as a midfielder for Belgian Pro League club Sint-Truiden.
Merlen is a product of the youth academies of the French clubs AMS Lensoise and Lens. On 26 June 2019, he signed his first professional contract with Lens, and the following year was promoted to their reserves. On 20 June 2022, he joined Belgian Division 1 club Liège. He helped the club earn promotion to the Challenger Pro League in his first season, and in the second season was named the club's Player of the Season. On 21 June 2025, he transferred to Sint-Truidense in the Belgian Pro League.
Merlen was called up to the France U16s for a set of friendlies in May 2017.