king of Parthia (reigned 123–88 BC); he was the son and successor of Artabanus II.

Mithradates recovered the eastern provinces that had been overrun by invading Śaka nomads during his father's reign. In the west he conquered Mesopotamia and defeated the Armenian king Artavasdes, whose son Tigranes (later Tigranes II) became a Parthian hostage and was redeemed only for the cession of 70 valleys. One of the most successful of the Parthian kings, Mithradates concluded the first treaty between Parthia and Rome in 92 BC.