| Mount Kujū | |
| Other Name: | 九重山 |
| Elevation M: | 1791 |
| Elevation Ref: | [1] |
| Prominence M: | 1791 |
| Listing: | Ultra 100 Famous Japanese Mountains |
| Language: | Japanese |
| Map: | Japan |
| Map Size: | 270 |
| Location: | On the border of Kokonoe and Taketa, Ōita, Japan |
| Range: | Kujū Mountains |
| Coordinates: | 33.0817°N 131.24°W |
| Type: | Stratovolcano |
| Last Eruption: | 1995 to 1996 |
, located on the border of Kokonoe and Taketa in Ōita Prefecture, Japan, is a stratovolcano in Kyushu Island, Japan, with a summit elevation of 1791m (5,876feet). It is one of the 100 Famous Japanese Mountains. It is part of the Aso-Kujū National Park.
The Kujū range consists of a dozen or so volcanic bodies gathered in a region of 13 km east-west and 10 km north-south. The mountains in the range include:
The Kujū volcanic group is mainly composed of andesite and dacite, which is defined as the volcanic activity above the Miyagi pyroclastic flow deposit which formed about 200,000 years ago. The north and south areas of Mt. Kujū are plateau grasslands whose main industry is dairy farming.