| Yokoyama Dam | |
| Dam Crosses: | Ibi River |
| Location: | Ibigawa, Gifu Prefecture, Japan. |
| Dam Length: | 220.0 m |
| Dam Height: | 80.8 m |
| Construction Began: | 1957 |
| Opening: | 1964 |
| Res Capacity Total: | 43,000,000 m3 |
| Res Catchment: | 471.0 km2 |
| Res Surface: | 170 hectares |
| Coordinates: | 35.5931°N 136.4553°W |
is a dam in Ibigawa, in the Gifu Prefecture of Japan.