| Mount Koizumi | |
| Other Name: | 小泉岳 |
| Elevation M: | 2158 |
| Prominence M: | 38 |
| Parent Peak: | Mount Hakuun |
| Listing: | List of mountains and hills of Japan by height |
| Location: | Hokkaidō, Japan |
| Range: | Daisetsuzan Volcanic Group |
| Coordinates: | 43.6672°N 142.9211°W |
| Topo: | Geographical Survey Institute 25000:1 白雲岳 25000:1 層雲峡 50000:1 大雪山 50000:1 旭岳 |
| Map: | Japan#Japan Hokkaido |
| Type: | stratovolcano |
| Volcanic Arc/Belt: | Kurile arc |
is a stratovolcano located in the Daisetsuzan Volcanic Group of the Ishikari Mountains, Hokkaidō, Japan.