| Myōshōji | |
| Subdivision Type1: | Country |
| Subdivision Name1: | Japan |
| Subdivision Type3: | Region |
| Subdivision Name3: | Kantō |
| Subdivision Type4: | District |
| Subdivision Name4: | Suginami Ward, Nakano Ward, Shinjuku Ward |
is designated as a Class A river by the Japanese government with a length of 9.7 km and a basin area of 21.4 km².
It starts in the Myōshōji Temple pond in Suginami Ward, and joins the Egota River later on. It flows into the Kanda River (Takadanobaba Channel) in Shinjuku Ward.
Due to the progress of urbanization, the water retention capacity of the Myōshōji River has fallen and there is an increasing risk of water damage. To cope with this situation, the Tokyo Metropolitan Government has constructed revetments that can handle rainfall of up to 50 millimeters per hour.