Although it is commonly agreed that the ancient Celts practiced human sacrifice, we know relatively little about how and why they engaged in this practice. The Celts did not have a written language to record their practices, so our understanding of how they performed human sacrifice comes from historical accounts provided by Greek and Roman contemporaries and from archaeological evidence of these ritual practices. A cross-cultural comparison of ritual human sacrifice in other societies is conducted in order to provide a framework for understanding the purpose of this practice in Celtic society.