HNK

HNK may refer to:
 * Croatian National Corpus (Croatian: Hrvatski nacionalni korpus)
 * Croatian National Theatre (disambiguation) (Croatian: Hrvatsko narodno kazalište)
 * Fist of the North Star (Japanese: Hokuto no Ken) a manga and its franchise
 * Honokiol, a lignan
 * Hydroxynorketamine, a metabolite of ketamine
 * Land of the Lustrous (Japanese: Hōseki no Kuni) a manga