X (disambiguation)

X or χ (the letter "chi") may refer to:
 * The χ-Blade, a legendary weapon introduced in Kingdom Hearts Birth by Sleep.
 * The Recusant's Sigil, represented as an X.
 * Hunter-X, a powerful enemy ship in Kingdom Hearts II.
 * Luxord, number X in Organization XIII.
 * Kingdom Hearts χ, an upcoming Kingdom Hearts game exclusive to PC browsers.