Uganda has one of the highest fertility rates globally, but only 30% of women report using an effective method of contraception. In Uganda, religious beliefs and other community norms that conflict with contraceptive use often challenge the provision of family planning services. Understanding the role of religion and related community beliefs in contraceptive use could inform the development of culturally appropriate demand generation interventions for low and middle-income settings. This qualitative study explored the role of religious and community norms on family planning in a rural Ugandan community with a mixed Muslim and Christian population. Between June and October 2020, we conducted four focus group discussions with men and women separately (N=26) who had an unmet need for family planning, and 15 key-informant interviews with religious and community leaders and family planning stakeholders (i.e., providers, district health officials), analyzed through thematic analysis. Men commonly cited their religion’s disapproval of family planning to justify their own disapproval. However, many religious leaders were in favor of family planning locally as a means to reduce poverty. Religious norms that interfered with family planning included the belief that each child was a gift from god, that using contraceptives was equivalent to killing children, and that each man should have multiple wives (i.e., religious polygamy). The community belief that each child brings their own success or luck, and that having children with different women increases the chances of having a successful/lucky child, was common regardless of religion, justifying polygamy and negatively impacting family planning. Polygamy led to women’s relationship dissatisfaction and family financial strain, resulting in some women using contraceptives in secret. However, among other women, polygamy resulted in competition between co-wives to produce more children. Broader gender norms supported polygamy, and tied men’s status to large family size. This study underscores the influence of religion in community norms about family planning. Participants cited religious norms in opposition to family planning that were not consistent with the current teachings of local religious leaders. Community sensitization that involves religious leaders who support family planning may increase community approval of family planning, especially among men.