X can refer to:
* The ''VideoGame/{{X}}-Universe'' series, a long-running series of wide open sandbox games.
* Music/{{X}}, a punk band.
* ''Manga/{{X 1999}}'', a manga series referred to as ''X'' in Japan.[[note]]renamed to this in America to avoid confusion with an already-existing comic series[[/note]]
* ''ComicBook/{{X}}'', a comic book series by Creator/DarkHorseComics.

Tropes [[Series/SesameStreet brought to you by the letter X]]:
* LetXBeTheUnknown
* XMakesAnythingCool

See ThisTropeIsX for tropes in which "X" is a placeholder.

You may also have been looking for the TurnBasedTactics series ''VideoGame/{{XCOM}}''.