National Route 17 is a highway on the island of Honshū in Japan. It originates at Nihonbashi in Chūō, Tokyo and terminates in the city of Niigata (the capital of Niigata Prefecture), where it meets Routes 7, 8, 49, 113 and 116).
Route 17 measures 351.1 km in length. It incorporates parts of two ancient highways, the Nakasendō and Mikuni Kaidō. The newer Kan-Etsu Expressway parallels Route 17.
In addition to Chūō, Route 17 passes through Itabashi. It links the prefectural capitals of Saitama (Saitama Prefecture) and Maebashi (Gunma Prefecture).