Obsidian, a volcanic glass

Obsidian (comics), a DC Comics character

Obsidian (computer game), a 1996 adventure game developed by Rocket Science Games

Obsidian (Transformers), a Transformers character

Obsidian Order, the fictional Cardassian intelligence agency from Star Trek

Obsidian Entertainment, a software developer

Obsidian (1986 Game), a 1986 game written for the Amstrad CPC.

Cursed Obsidian, the GEM used by the Valkyrjies in My-Otome.