Unclean meats are meats that religious dietary laws forbid as unfit to eat — most fully developed in Judaism’s kosher laws, which prohibit pork, shellfish, and other specified animals, and require permitted animals to be slaughtered in a prescribed way. Similar concepts appear in Islam’s halal rules and in other traditions. The categories rest on scriptural command rather than modern food science, though some forbidden animals do carry higher parasite risks. For observant communities these laws shape the entire food system: separate supply chains, certified slaughterhouses, and supervised kitchens. Food manufacturers seeking kosher or halal certification must exclude unclean meats and prevent cross-contact, making the ancient categories a live commercial reality.