XK

XK may refer to:
 * XK (protein), a protein responsible for Kx antigen which helps determine a person's blood type
 * XK (2015 album), by Brendan Croskerry
 * Jaguar XK, a car series made by Jaguar
 * Jeep Commander XK, a SUV made by Jeep
 * Republic of Kosovo, ISO 3166-1 alpha-2 user-assigned code element XK (user assigned code)
 * CCM Airlines (IATA airline designator XK)
 * X-K aka X Kryptonite