Kalhor is a Kurdish tribe and their dialect has been as categorized a southern branch of Southern Kurdish.
The tribe is described as the most powerful tribe mainly in the province of Kermānšāh and other parts of the region as "one of the most ancient, if not the most ancient, of the tribes of Kurdistan". The Kelhors were already mentioned by Šaraf-al-Din Bedlisi in the late 16th century, according to whom, the chiefs of the Kalhor claimed to be descended from Gudarz, son of Giv (q.v.), a major hero in the Shahnameh
The majority of the Kalhors are Shiites, while others are followers of the Yarsanism.