Iwayato Dam (Japanese: 岩屋戸ダム) is a gravity dam located in Miyazaki Prefecture in Japan.

The dam is used for power production.

The dam impounds about 39 ha of land when full and can store 8309 thousand cubic meters of water.

The construction of the dam was started on 1920 and completed in 1941.

This article about a dam or floodgate on Kyushu, Japan is a stub.