Tryon Creek is a 4.85-mile (7.81 km) tributary of the Willamette River in the U.S. state of Oregon. Part of the drainage basin of the Columbia River, its watershed covers about 6.5 square miles (16.8 km2) in Multnomah and Clackamas counties. The stream flows southeast from the Tualatin Mountains through the Multnomah Village neighborhood of Portland and the Tryon Creek State Natural Area to the Willamette in the city of Lake Oswego. Parks and open spaces cover about 21 percent of the watershed, while single-family homes dominate most of the remainder. The largest of the parks is the state natural area, which straddles the border between the two cities and counties.

The Tryon Creek State Natural Area is a state park located primarily in Portland, in the U.S. state of Oregon. It is the only Oregon state park within a major metropolitan area. The 645-acre (261 ha) park lies between Boones Ferry Road and Terwilliger Boulevard in southwest Portland in Multnomah County and northern Lake Oswego in Clackamas County and is bisected from north to south by Tryon Creek. To the north, the park abuts the Lewis & Clark Law School campus.