The relationship between religion and happiness has been the focus of much research. The present review provides a critical examination of this research and, in particular, focuses on conceptual and methodological concerns. The majority of studies report a positive association between measures of religion and happiness; however, contradictory findings are common. This is exemplified in the literature that has systematically employed the Francis Scale of Attitude toward Christianity alongside two different measures of happiness among a variety of samples. Two opposing conclusions have found consistent support. Research with the Oxford Happiness Inventory has consistently found religiosity to be associated with happiness, while research employing the Depression-Happiness Scale has consistently found no association. It is argued that such contradictions may reflect both conceptual and methodological weaknesses in this literature.