Black cube

Black cube may refer to:
 * Black Cube, a private intelligence agency
 * Black Cube Nomadic Art Museum, a nonprofit contemporary art organization producing site-specific art in the public realm.
 * Blackballing, a vote of rejection in a secret ballot
 * The Kaaba, a black cubical building at the center of the Grand Mosque of Mecca; it is the most sacred site in Islam
 * Tefillin, a small black leather cube used by Jews during prayer