The Miami River is a stream, approximately 13 miles (21 km) long, on the coast of northwest Oregon in the United States.

It drains a mountainous timbered region of the Northern Oregon Coast Range west of Portland, into Pacific Ocean.

Descending swiftly from 1,782 feet (543 m) to near sea level, the Miami does not pass through any communities.

[6] The river's name is based on the Chinook Jargon phrase Mi-me Chuck, meaning a tributary or downriver stream.

[7] Flowing generally southwest through the forest, the Miami River receives Prouty Creek from the right about 5.5 miles (8.9 km) from the mouth.