is a type of volcanic glass.
Obsidian may also refer to:
- Obsidian (comics), a DC Comics character
- Obsidian (1986 Game), a 1986 game written for the Amstrad CPC.
- Obsidian (computer game), a 1996 adventure game developed by Rocket Science Games
- Obsidian (Transformers), a Transformers character
- Obsidian Entertainment, a software developer
- Obsidian (RPG), a roleplaying game
- Obsidian Order, the fictional Cardassian intelligence agency from Star Trek
- Cursed Obsidian, the GEM used by the Valkyrjies in My-Otome.
- Obsidian, an instrumental track on Swedish metal band Meshuggah's fourth studio album, Nothing.