Background <p>Suicide remains a critical public health issue in Hungary, a country with historically high suicide rates. This study investigates the relationship between regional religious affiliation and suicide mortality from 2000 to 2022, shedding light on the influence of social and cultural factors in suicide prevention.</p> Methods <p>Data were sourced from the national population register and the three most recent censuses. We applied quantile and gamma regressions to explore the associations between age-standardised suicide rates and the age-standardised incidence rates of religious affiliation across regions, reflecting the religious composition.</p> Results <p>Our findings confirm a continued nationwide decline in suicide mortality, yet regional variations persist, particularly in relation to religious affiliation. Suicide rates were significantly lower in regions with higher proportions of Roman Catholics (<i>p</i> = 0.008) and higher in areas with a greater percentage of non-religious individuals (<i>p</i> = 0.007). These trends held steady before and during the COVID-19 pandemic. Notably, the geographic distribution of Catholics and suicide rates displayed opposing patterns across Hungary’s eight statistical regions.</p> Conclusions <p>These results, based on robust census data, suggest that Catholic affiliation may have a protective effect against suicide, potentially through enhanced social cohesion and community support. Understanding these regional patterns can inform more targeted mental health interventions and highlight the critical role of social and cultural factors in suicide prevention.</p>