This paper addresses trans-oceanic connectivity in the period from the third century BCE to the sixth century CE, through the perspective of multi-religious networks across the Indian Ocean and underscores differences between the western Indian Ocean and those that spread across the Bay of Bengal. Though there is evidence for the circulation of Buddhism from Egypt in the west to Vietnam in the east, Christianity is by and large limited to the western Indian Ocean. Across the Bay of Bengal, Buddhism was coterminous with Hinduism. These long-distance networks coexisted with local and regional cults indicating plurality in the religious landscape of the Indian Ocean world. Coastal shrines and ritual worship across the waters corroborate the sharing of architectural vocabulary and practices and inform us of the multiple functions of what is often termed trade goods. These multi-religious networks are crucial as recent research has moved beyond the colonial paradigm of invoking incontrovertible blocs of South and Southeast Asia while studying mobility across the Indian Ocean.