Religion and artificial intelligence are now deeply enmeshed in humanity's collective imagination, narratives, institutions, and aspirations. Their growing entanglement also runs counter to several dominant narratives that engage with long-standing historical discussions regarding the relationship between the 'sacred” and the 'secular' - technology and science. This Cambridge Companion explores the fields of Religion and AI comprehensively and provides an authoritative guide to their symbiotic relationship. It examines established topics, such as transhumanism, together with new and emerging fields, notably, computer simulations of religion. Specific chapters are devoted to Judaism, Christianity, Islam, Hinduism, and Buddhism, while others demonstrate that entanglements between religion and AI are not always encapsulated through such a paradigm. Collectively, the volume addresses issues that AI raises for religions, and contributions that AI has made to religious studies, especially the conceptual and philosophical issues inherent in the concept of an intelligent machine, and social-cultural work on attitudes to AI and its impact on contemporary life. The diverse perspectives in this Companion demonstrate how all religions are now interacting with artificial intelligence.