Greco-Roman religion refers to the religious systems, cults, and theological ideas that characterized the cultures of the ancient Greco-Roman world. The traditions of Greek religion and Roman religion developed independently and became interleaved through cultural exchange, conquest, and philosophical synthesis, especially during the Hellenistic period and the height of the Roman Empire.
In both Greek and Roman contexts, religion was deeply embedded in public life, involving practices such as sacrifice, divination, and temple ritual. Gods and goddesses were venerated as powers active in the cosmos and the city, often associated with natural forces, civic virtues, and mythic narratives. The Greek pantheon and Roman pantheon overlapped significantly, with Roman deities often interpreted through the lens of interpretatio graeca—the identification of Roman gods with their Greek counterparts.