A growing body of research is exploring the association between religiosity and drug use. Thus, this analysis examines the association between religiosity and substance use patterns among females in the criminal justice system. Data derived from 318 women recruited from a Municipal Drug Court System in St. Louis, Missouri, were used to determine the association between religiosity and substance use patterns. Results indicate that religiosity decreased the odds of cocaine use, observed for both crack/cocaine (CC) use alone (adjusted odds ratio [AOR] = 0.41) and crack/cocaine + marijuana (CC + MJ) (AOR = 0.32). Interestingly, this association was not found for MJ use alone. Other variables that were significantly associated with CC + MJ use included being non-Black (CC + MJ: AOR = 0.46; MJ: AOR = 0.28), 4+ arrests (CC + MJ: AOR = 4.66; CC: AOR = 2.64), and <30 years of age (CC + MJ: AOR = 0.37; CC: AOR = 0.16; MJ: AOR = 2.84). Future drug prevention and interventions should consider the potential protective effects of religiosity on substance use.