Findings since 2000 about the association between the frequency of religious service attendance (formal religiosity) and sexual risk taking in adolescents and emerging adults were explored. A systematic literature search (April 2020) focused on articles with data on religiosity and age at sexual debut, number of sexual partners, condom use at most recent sexual intercourse, and consistent condom use. A total of 27 studies with 37,430 participants ( Mage = 18.4, range: 12–25, 43.5% male) were included. In random-effects meta-analysis, the link between formal religiosity and sexual risk taking was significant only for age at sexual debut (r = 0.09, 95% CI = 0.05, 0.13) and the number of sexual partners ( r = −0.14, 95% CI = −0.19, −0.09). Weak associations between the constructs of interest indicate that formal religiosity is not sufficient to protect young people’s sexual health.