Kerek is an extinct language of Russia of the northern branch of the Chukotko-Kamchatkan languages. On historical linguistic grounds it is most closely related to Koryak (both languages have a merger of the proto-Chuktotian phonemes /*ð/ and /*r/ with /*j/). The next closest relative is Chukchi (/*ð/ and /*r/ are merged, but not /*j/).