The Breitenbush River is a tributary of the North Santiam River in western Oregon in the United States. It drains a rugged, forested area of the Cascade Range east of Salem. The North and South forks flow west, joining 0.25 miles (400 m) east of the small community of Breitenbush. The combined stream flows generally west-southwest through the Willamette National Forest. It joins the North Santiam at Detroit.