| Rapid River | |
| Pushpin Map: | Canada Ontario |
| Pushpin Map Caption: | Location of the mouth of the Rapid River in Ontario |
| Subdivision Type1: | Country |
| Subdivision Name1: | Canada |
| Subdivision Type2: | Province |
| Subdivision Name2: | Ontario |
| Subdivision Type3: | Region |
| Subdivision Name3: | Northwestern Ontario |
| Source1: | Unnamed marsh |
| Source1 Location: | Unorganized Sudbury, Sudbury District |
| Source1 Coordinates: | 46.8861°N -81.16°W |
| Source1 Elevation: | 430m (1,410feet) |
| Mouth: | Vermillion River |
| Mouth Location: | Greater Sudbury |
| Mouth Coordinates: | 46.6861°N -81.0231°W |
| Mouth Elevation: | 282m (925feet) |
The Rapid River is a river in Sudbury District and Greater Sudbury in Northwestern Ontario, Canada. It begins at an unnamed marsh, at an elevation of 430m (1,410feet) and just upstream of Osbourne Lake, in Unorganized Sudbury, Sudbury District. It travels south to its mouth at the Vermillion River at an elevation of 282m (925feet), near the community of Val Thérèse in Greater Sudbury.