Religion and spirituality in the family is a burgeoning field of inquiry. This Element begins by providing basic definitions, theoretical underpinnings, and common assessments of religion and spirituality (R/S) within the family. The authors also examine individuals' religious and spiritual (R/S) landscapes in relation to family functioning, and then consider positive psychology dimensions such as gratitude, humility, compassion, and forgiveness within the context of family members' religiousness and spirituality. Finally, interventions focused on R/S in the family unit and children's medical complications in relation to R/S factors and familial functioning are discussed. Conclusions include recommendations for future research and clinical practice to support families via an R/S lens.