The Priest River is a 68-mile (109 km) long tributary of the Pend Oreille River in the U.S. state of Idaho. It is part of the Columbia River basin, as the Pend Oreille River is a tributary of the Columbia River. The river's drainage basin is 980 square miles (2,500 km) in area.

The river was named for a Roman Catholic priest, Father Roothaan.

The Priest River originates in Upper Priest Lake and flows south into Priest Lake. It exits the south end of Priest Lake and flows south to the Pend Oreille River near the city of Priest River. The Upper Priest River, which is sometimes considered part of the Priest River proper, originates near the US-Canada border and flows south into Upper Priest Lake.

The Priest River has three major tributaries. On the left, there is the East River. This river has about twenty tributaries itself, and flows into the Priest about 1 mile from Big Creek. On the right there is the Upper West Branch of the Priest River, and the Lower West Branch of the Priest River. These never merge. The Lower West Branch is more popular, this has Torelle Falls on it.

List:

• Indian creek
• Lion creek
• Hunt creek
• Soldier creek
• Quartz creek
• Upper west branch Priest River
• Lower west branch Priest River
• East River
• Big creek
• Blue creek

• List of Idaho rivers
• List of longest streams of Idaho
• Tributaries of the Columbia River