| Shahriyar IV شهریار | |
|---|---|
| Husam al-Dawla | |
 Coin of Shahryar IV. | |
| King of Mazandaran | |
| Reign | 1074–1114 |
| Predecessor | Qarin II |
| Successor | Qarin III |
| Born | 1039 Mazandaran |
| Died | 1114 (aged 74 or 75) Tamisha, Mazandaran |
| Issue | Qarin III Ali I Rustam Yazdagird Bahram |
| Dynasty | Bavand dynasty |
| Father | Qarin II |
| Religion | Twelver Shia Islam |
Shahriyar IV (Persian: شهریار), also known by his honorific title Husam al-Dawla (حسام الدوله), was the king of the Bavand dynasty of Mazandaran, ruling from 1074 to 1114.
After having succeeded his father Qarin II in 1074, Shahriyar IV immediately moved the capital to Sari, which it would remain till 1210. A few decades later, he briefly waged a war against his overlords, the Seljuk Empire. Peace was made, and Shahriyar IV's son Qarin III married a daughter of the Seljuk Sultan Muhammad I.
Shahriyar IV's rule was shortly usurped by Qarin III, who, however, eventually restored him as king. Shahriyar, old and ill, spent the rest of his reign as a figurehead, whilst Qarin III was the de facto ruler of the kingdom, and finally ascended the throne after Shahriyar IV's death in 1114.