The Friedrichshafen Stadt–Friedrichshafen Hafen railway (or Friedrichshafen City–Friedrichshafen Port railway; German: Bahnstrecke Friedrichshafen Stadt–Friedrichshafen Hafen) is a standard gauge and non-electrified railway line in the city of Friedrichshafen in the German state of Baden-Württemberg. It connects the town station with the port station. The 816 metre-long branch line has its own VzG route number, 4531, although operationally it is a connection between two parts of the same station.