The Citadel is the name of maps in both Doom II and Heretic, as well as the Hexen expansion pack, Deathkings of the Dark Citadel:
- MAP19: The Citadel is the Doom II level.
- E1M5: The Citadel is the Heretic level.
- MAP13: Dark Citadel (Doom 64)
- Citadel (Doom Eternal) can refer to a number of locations in Doom Eternal, an area at the end of Hell on Earth (Doom Eternal), and an area in Nekravol