France's secular political culture, Catholic heritage, and tumultuous relationship with Islam have had a significant impact on 21st-century interpretations, perceptions, and politicisations of religious education in French society. Since religious education is relegated to the French private school system, it is decentralised, complex, and vastly plural -- especially compared to France's hyper-centralised public education. Religious education's plurality and decentralisation have deepened with the recent expansion of Muslim and independent schooling. This article offers a comparative analysis of the variety of interpretations and manifestations of religious education across France's private education system. Drawing upon extensive ethnographic fieldwork carried out in more than fifteen French private Muslim, Catholic, and secular schools intermittently from 2012 to 2020, I illustrate how Catholic school actors and supposedly 'secular' school actors imparting Christian culture can operate with significantly more freedom than their Muslim school counterparts. Despite significant variation in approaches to religious education across the system, religious education in Muslim schools is quite parallel to other schooling communities. Nonetheless, Muslim school actors face disproportionate barriers to equitable treatment. This discrimination is facilitated by the complexities and ambiguities of RE and is representative of efforts to restrict the imparting of Muslim culture(s) to youth in French schools.