The Nuttlar–Frankenberg railway is a 62.3 km long line from Nuttlar on the Upper Ruhr Valley Railway in the German state of North Rhine-Westphalia via Winterberg and Allendorf (Eder) to Frankenberg (Eder) in the state of Hesse.

Numerous engineering structures were required between Winterberg and Bromskirchen, including three tunnels and a viaduct, with a grade of up to 2.5%.

From 1910/1911 it was possible to continue the journey over the Upper Eder Valley Railway from Allendorf to Bad Berleburg.

Special trains often ran between the Ruhr area and Winterberg for winter sports traffic.

Regional-Express service RE 57 (Dortmund-Sauerland-Express) from/to Dortmund runs between Bestwig and Winterberg every two hours, and hourly on weekends, operated with Alstom Coradia LINT 41 (class 648) diesel rail cars, partly in multiple, often mixed with LINT 27 (class 640) rail cars.