Hormizd IV (also spelled Hormozd IV or Ohrmazd IV; Middle Persian: 𐭠𐭥𐭧𐭥𐭬𐭦𐭣) was the King of Kings of Sasanian Iran from 579 to 590. He was the son and successor of Khosrow I (r. 531–579) and his mother was a Khazar princess.
During his reign, Hormizd IV had the high aristocracy and Zoroastrian priesthood slaughtered while supporting the landed gentry (the dehqans). His reign was marked by constant warfare: to the west, he fought a long and indecisive war with the Byzantine Empire, which had been ongoing since the reign of his father; and to the east, the Iranian general Bahram Chobin successfully contained and defeated the Western Turkic Khaganate during the First Perso-Turkic War. It was also during Hormizd IV's reign that the Chosroid dynasty of Iberia was abolished. After negotiating with the Iberian aristocracy and winning their support, Hormizd successfully incorporated Iberia into the Sasanian Empire.