BackgroundNumerous national public inquiries have highlighted the problem of child sexual abuse in religious organizations. Despite this, evidence of population-wide prevalence is scarce. ObjectiveTo provide the first nationally representative prevalence estimates of child sexual abuse perpetrated by adults in religious organizations in Australia. MethodsThe Australian Child Maltreatment Study (ACMS) surveyed 8503 people aged 16 and over about their experiences of child maltreatment. Weighted prevalence estimates were calculated based on responses to the child sexual abuse questions from the Juvenile Victimization Questionnaire-R2: Adapted Version (ACMS). ResultsOne in 250 people reported being sexually abused as a child by an adult in a religious organization (0.4 %, 95 % CI, 0.3–0.6 %). Men reported significantly higher rates of child sexual abuse by these perpetrators (0.8 %, 95 % CI, 0.5–1.2 %), compared to women (0.1 %, 95 % CI, 0–0.3 %). This type of sexual abuse was overwhelmingly perpetrated by men (0.4 %, 95 % CI, 0.3–0.6 %), compared to women (0 %, 95 % CI, 0–0.1 %), and was substantially more often experienced in Catholic organizations (71.9 %) than other Christian denominations or other religions. Prevalence of child sexual abuse in religious organizations has declined over time (2.2 % of men 65 years and older, compared with 0.2 % of 16–24-year-old men). ConclusionsChild sexual abuse has been widespread in religious organizations in Australia. A decline over time indicates progress has been made in preventing sexual abuse of children. Religious organizations must take all reasonable measures to prevent child sexual abuse, with a particular need for interventions targeting male leaders, and organizational cultures.