Mount Tengu (天狗岳, Tengu-dake) is a mountain on the border of Chino and Koumi of Nagano in Japan.

The main traverse route of the Yatsugatake Mountain Range passes through the eastern summit of Mount Tengu.

In addition, there are mountain trails on the western side of Mount Tengu from Shibunoyu, 1,880 m (6,168 ft), in Oku-Tateshina Onsen Village and from Karasawa Kosen, and on the eastern side from Inakoyu via Honzawa Onsen.

A mountain hut, Kuroyuri Hutte, 2,400 m (7,874 ft), is located at Kuroyuridaira, just west of Nakayama Pass (中山峠, Nakayamatōge), where the mountain trail from Shibunoyu joins the main traverse route.

The trail is approximately 2.5 hours from Shibunoyu to Kuroyuri Hutte, and then 90 minutes to Higashi Tengu.