The Opir River (Ukrainian: О́пір) is located in Ukraine, within Stryi Raion of Lviv Oblast.

The Opir River originates on the eastern slope of Velykyi Yavirnyk Mountain (Ukrainian: Великий Явірник) in the Verkhovynskyi Range [uk], south of the village of Oporets [uk].

It flows into the Stryi River between the town of Verkhnie Synovydne and the village of Mezhybrody.

The river supplies water for settlements and for the irrigation of agricultural lands.

Several settlements are located on the river (in order from the source to the mouth): Oporets [uk], Lavochne, Ternavka, Slavske, Tukhlia, Hrebeniv, Skole, Dubyna, Verkhnie Synovydne.