| Mount Neishi | |
| Other Name: | 根石岳 |
| Elevation M: | 2603 |
| Listing: | List of mountains and hills of Japan by height |
| Language: | Japanese |
| Pronunciation: | pronounced as /ja/ |
| Location: | On the border of Chino and Koumi of Nagano in Japan |
| Range: | Northern Yatsugatake Volcanic Group |
| Coordinates: | 36.0156°N 138.3603°W |
| Type: | Stratovolcano |
is a 2,603m mountain on the border of Chino and Koumi of Nagano in Japan. This mountain belongs to Northern Yatsugatake Volcanic Group.
Mount Neishi is a stratovolcano. This mountain is a part of the Yatsugatake-Chūshin Kōgen Quasi-National Park., 26030NaN0, is to the north, along the main traverse route of the Yatsugatake Mountain Range, and Mount Nishi Tengu, 26460NaN0, is to the northwest. There is trail from to, through Mount Higashi Tengu, to Mount Neishi. Additionally, there is a trail heading east to, on the pass between Mount Higashi Tengu and Mount Neishi.
, 25900NaN0,, 24230NaN0, and Mount Iō, 276030NaN0 are located to the south. A lodge,, is located on the south side, 15 minutes from the peak.. The lodge is open April to November. [1] The main traverse route of the Yatsugatake Mountain Range passes through the summit of Mount Neishi.