Sumpter Valley Railway, Heritage railway and historic district in Baker County, Oregon.

The Sumpter Valley Railway runs a 3 ft (914 mm) narrow-gauge heritage line between McEwen and Sumpter in Baker County, Oregon. A black steam locomotive with a green passenger car lettered "SUMPTER VALLEY RAILWAY" pulls excursion trains on the roughly 5-mile (8.0 km) route. The railroad owns two steam locomotives and other rolling stock.

Originally constructed in 1890 to serve Oregon's gold mining communities and logging operations, the railway connected remote towns like Sumpter and Prairie City, playing a crucial role in regional development before passenger service ended in 1937.

The railway's name comes from the Sumpter Valley it served. Today volunteers of Sumpter Valley Railroad Restoration Inc. run and maintain the line; the Prairie City passenger station, renovated in the 1970s, has housed the DeWitt Museum since 1984, displaying lanterns, lights, railway artifacts and photographs of train wrecks and life along the line.

The heritage railway operates weekend and holiday excursions from Memorial Day through September, with tickets available online and departures from the restored Sumpter Depot on Austin Street, featuring a museum and gift shop.

The railway features one of the few remaining operational Heisler steam locomotives in North America, along with a former Chiquita Banana company locomotive that was restored and added to service in 2018.