| Lake of Bays River | |
| Pushpin Map: | Canada Ontario |
| Pushpin Map Caption: | Location of the mouth of the Lake of Bays 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: | Unnamed lake |
| Source1 Coordinates: | 48.2806°N -79.7008°W |
| Source1 Elevation: | 450m (1,480feet) |
| Mouth: | Conver Lake, on the Sturgeon River |
| Mouth Coordinates: | 50.115°N -91.1756°W |
| Mouth Elevation: | 375m (1,230feet) |
| River System: | Nelson River drainage basin |
The Lake of Bays River is a river in Kenora District in Northwestern Ontario, Canada.[1] It is in the Hudson Bay drainage basin and is a left tributary of the Sturgeon River.
The river begins at an unnamed lake just west of Ontario Highway 599 and just west of the border with Thunder Bay District. It heads north, then west through Rome Lake, Gibraltar Lake, Malta Lake and Handcuff Lake to the Lake of Bays, where it takes in the left tributaries Dominion River and Bays River. It then heads north, and reaches its mouth at Conver Lake on the Sturgeon River. The Sturgeon River flows via the Marchington River, English River, Winnipeg River, and Nelson River to Hudson Bay.