Matsunoyama (松之山町, Matsunoyama-machi) was a town located in Higashikubiki District, Niigata Prefecture, Japan.
As of 2003, the town had an estimated population of 2,974 and a density of 34.46 persons per km². The total area was 86.31 km².
On April 1, 2005, Matsunoyama, along with the town of Matsudai (also from Higashikubiki District), the town of Kawanishi, and the village of Nakasato (both from Nakauonuma District), was merged into the expanded city of Tōkamachi. It is located on the southeastern portion of the city.
Matsunoyama is home to one of the big three medicinal hot springs of Japan, along with Kusatsu (Gunma Prefecture) and Arima Onsen (Hyogo Prefecture). One of the main roads in the town is lined with about a dozen traditional Japanese-style hot spring resorts, attracting many visitors.
According to legend, a woodcutter discovered the hot springs 700 years ago when he saw a hawk resting its injured wing in it. It has also been told that the daughter of Uesugi Fusayoshi (the 15th century governor of Echigo Province, current Niigata Prefecture) cured her skin disease by soaking in the hot springs.
Matsunoyama is also famous for the massive amount of snowfall it receives, with 2 to 3 meters on average during the severe winter months.