Saint Paul's Union Depot is an historic railroad station and intermodal transit hub located in the Lowertown neighborhood of the city of Saint Paul, Minnesota, United States. It serves inter-city rail, inter-city bus, and local bus services. The METRO Green Line light rail has a stop outside the station's headhouse. At one time the Saint Paul Union Depot Company controlled 9.24 miles of St. Paul trackage and terminal facilities, including the depot building.