Usta is a river in Nizhny Novgorod and Kirov Oblast, Russia. It is a left tributary of the Vetluga River (Volga's tributary). It is 253 km in length, with a drainage basin of 6030 km². Most of its water comes from melting snow. The average discharge 47 km from its mouth is 28 m³/s. The Usta freezes over in November, and stays icebound until April. It is navigable on its lower reaches. The town of Uren is situated by the Usta.