A Black Emerald is a black-colored gemstone, often resembling a Chaos Emerald. Black Emerald may refer to:
- Ancient Onyx, an emerald used to imprison Chaos in the Sonic the Hedgehog comic series and its spin-offs published by Archie Comics; or
- Black Emerald (Sonic the Comic), an emerald from the Shadow Dimension in the Sonic the Comic series published by Fleetway Editions.