Citadel (disambiguation)

The Citadel may refer to:
 * Citadel (Level), one of the maps that will ship with Halo 3: ODST.
 * Citadel (Covenant), the Covenant structure used in Halo Wars.
 * Citadel (Forerunner), the Forerunner structure located on the Ark.
 * Battle of the Citadel, the last major battle to be fought in the Human-Covenant War.
 * The Citadel Skull achievement, claimed by obtaining the Citadel Skull.