Balch Creek is a 3.5-mile (5.6 km) tributary of the Willamette River in the U.S. state of Oregon. Beginning at the crest of the Tualatin Mountains, the creek flows generally east down a canyon along Northwest Cornell Road in unincorporated Multnomah County and through the Macleay Park section of Forest Park, a large municipal park in Portland. At the lower end of the park, the stream enters a pipe and remains underground until reaching the river. Danford Balch, after whom the creek is named, settled a land claim along the creek in the mid-19th century. After murdering his son-in-law, he became the first person legally hanged in Oregon.