Quhyar (Persian: کوه یار), was the ruler of the Qarinvand dynasty, ruling briefly in 839 until his assassination.
Quhyar was the son of Qarin ibn Vindadhhurmuzd, and had a brother named Mazyar, who, after ascending the Qarinvand throne, was repelled from Tabaristan by his uncle Vinda-Umid and the Bavandid ruler Shahriyar I.
Mazyar, however, later rebelled against the Abbasid Caliphate, an act which was widely supported by the native Zoroastrians, who began plundering the Muslim villages.
[1] The Tahirid ruler Abdallah ibn Tahir al-Khurasani and the Abbasid caliph al-Mu'tasim shortly sent five corps that entered Tabaristan from all sides.
However, the fall of Tabaristan went quickly: several cities were caught by surprise, while Qarin I betrayed Mazyar and agreed to aid the Abbasids in exchange for being restored as the ruler of the Bavand dynasty.