This paper investigates religious discrimination in the French labour market, based on a large correspondence test during which 6,231 applications were sent in response to job announcements nation-wide for accountants. Religious discrimination is measured by comparing the callback rates of 25-year-old male and female French applicants of Lebanese origin who are Catholics, Jews or Muslims. Results reveal that both Jews and Muslims are discriminated against relative to Catholics. But male Muslim applicants suffer the most from religious discrimination: they are nearly 4 times less likely to receive a job interview callback as compared to their Catholic counterparts. Additional features of the experimental set up aim to illuminate the mechanisms behind religious discrimination. Notably, fear for deviant religious practices within the firm seems to partly account for the low callback rate of Muslim male applicants. It is indeed to their advantage to signal attachment to the French laïcité. Moreover, stressing commitment to academic and professional excellence suffices to annihilate religious discrimination against Jewish and Muslim female applicants. Distressingly however, such commitment exacerbates religious discrimination against Jewish and Muslim male applicants. In particular, submitting an outstanding rather than average application has no impact on the callback rate of Muslim male applicants.