Born in
Meyzieu in the
Metropolis of Lyon, Merah started his youth career at the local US Meyzieu. In July 2016, he joined the youth academy of region giants
Lyon. On 24 February 2025, on his 18th birthday, Merah signed his first professional contract with
Lyon, tying him to the club until June 2027. He captained Lyon under-19s side during the 2024–25 season, before being integrated to
Lyon reserves team that the end of the season, where he made his senior debut at the
Championnat National 3. Ahead of the
2025–26 season, Merah was promoted to
Lyon's first team by coach
Paulo Fonseca. He earned his first official appearance for Lyon on 16 August 2025 in a 1–0 away win over
Lens during the first matchday of the
2025–26 Ligue 1, coming in as a substitute in the 66th minute. Shortly after his professional debut, on 26 August, Merah extended his contract with Lyon until 2029. Five days later, he earned his first start for
Les Gones, playing 71 minutes in the 1–0 victory over
Marseille in the
Choc des Olympiques. Following his impressive performances, Merah was given the
Pépite du mois award for the best youth talent of the month in Ligue 1. ==International career==