Mohamed Oulhaj (Arabic: محمد أولحاج; born 6 January 1988 in Al Hoceima) is a former Moroccan footballer, who played as a defender for Raja Casablanca.

Jean-Yves Chay was the coach of Raja Casablanca when Oulhaj played his first official match with the team on September 22, 2007 against Olympique Khouribga in Complexe OCP.

On October 19, 2008, he scored his first goal in his professional career during a 5–0 winning match against Chabab Massira.

After Oulhaj's great performances with Raja Casablanca on the season of 2007–08, the former national coach Fathi Jamal call him firstly to represent Morocco against Ethiopia for the 2010 FIFA World Cup qualification but he didn't have a chance to play.

On June 14, 2008, he made his first match with the team in Kigali against Rwanda when Morocco lost 3–1.