| Poplar River | |
| Pushpin Map: | Canada Ontario |
| Pushpin Map Caption: | Location of the river mouth 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: | Unnamed lake |
| Source1 Coordinates: | 51.745°N -84.8458°W |
| Source1 Elevation: | 174m (571feet) |
| Mouth: | Atikameg River |
| Mouth Coordinates: | 51.8164°N -83.7178°W |
| Mouth Elevation: | 69m (226feet) |
| River System: | James Bay drainage basin |
The Poplar River is a river in northeastern Kenora District in northwestern Ontario, Canada.[1] It is in the James Bay drainage basin and is a left tributary of the Atikameg River.
The Poplar River begins at an unnamed lake and flows northeast, then east to its mouth at the Atikameg River. The Atikameg River flows via the Kapiskau River to James Bay.