| Cat River | |
| Pushpin Map: | Canada Ontario |
| Pushpin Map Caption: | Location of the mouth of the Cat River in Ontario |
| Subdivision Type1: | Country |
| Subdivision Name1: | Canada |
| Subdivision Type2: | Province |
| Subdivision Name2: | Ontario |
| Subdivision Type3: | Region |
| Subdivision Name3: | Northwestern Ontario |
| Subdivision Type4: | District |
| Subdivision Name4: | Kenora |
| Source1: | Cat Lake |
| Source1 Coordinates: | 51.5911°N -91.9117°W |
| Source1 Elevation: | 397m (1,302feet) |
| Mouth: | Lake St. Joseph |
| Mouth Coordinates: | 50.98°N -91.2994°W |
| Mouth Elevation: | 374m (1,227feet) |
| River System: | James Bay drainage basin |
The Cat River is a river in the Unorganized Part of Kenora District in Northwestern Ontario, Canada.[1] The river is part of the James Bay drainage basin, and flows from Cat Lake to Lake St. Joseph, the source of the Albany River, which flows to James Bay.