| Rainy Lake 18C | |
| Official Name: | Rainy Lake Indian Reserve No. 18C |
| Settlement Type: | Indian reserve |
| Pushpin Map: | Canada Ontario |
| Pushpin Mapsize: | 200 |
| Coordinates: | 48.7°N -115°W |
| Subdivision Type: | Country |
| Subdivision Type1: | Province |
| Subdivision Type2: | District |
| Subdivision Name2: | Rainy River |
| Subdivision Type3: | First Nation |
| Subdivision Name3: | Mitaanjigamiing |
| Area Land Km2: | 17.64 |
| Population Footnotes: | [1] |
| Population Total: | 125 |
| Population As Of: | 2021 |
| Population Density Km2: | 5.3 |
| Website: | www.mitaanjigamiing.ca |
Rainy Lake 18C is a First Nations reserve on Rainy Lake in Rainy River District, Ontario. It is the main reserve of the Mitaanjigamiing First Nation.