The study of comparative constitutional law and religion lies at the intersection of two relatively recent, but rapidly growing, scholarly fields: comparative constitutional law, and law and religion studies. The intersection between the two is natural and substantial, revealing the relationship between a state’s laws and religions and the tension between universalism and particularism generated by both modern constitutions and world religions. The potential complexity of internal and external relations within and between constitutions and religions is clear, and the powerful loyalties they evoke make their resolution particularly intractable. This original research review surveys 50 of the most significant scholarly works on the subject, offering valuable insight for everyone interested in the relationship between constitutional law and religion.