The Tillamook River is a stream, about 17 miles (27 km) long, near the coast of northwest Oregon in the United States. It drains an oceanside valley in the foothills of the Northern Oregon Coast Range west of Portland and empties into the Pacific Ocean via Tillamook Bay. It is one of five rivers—the Tillamook, the Trask, the Wilson, the Kilchis, and the Miami—that flow into the bay.

The Northern Oregon Coast Range is the northern section of the Oregon Coast Range, in the Pacific Coast Ranges physiographic region, located in the northwest portion of the state of Oregon, United States. This section of the mountain range, part of the Pacific Coast Ranges, contains peaks as high as 3,710 feet (1,131 m) for Rogers Peak. Forests in these mountains are considered to be some of the most productive timber land in the world. The Central Oregon Coast Range is directly south of this section with the Southern Oregon Coast Range beyond the central range.