| Clare River | |
| Pushpin Map: | Canada Southern Ontario |
| Pushpin Map Caption: | Location of the mouth of the Clare River in southern Ontario |
| Subdivision Type1: | Country |
| Subdivision Name1: | Canada |
| Subdivision Type2: | Province |
| Subdivision Name2: | Ontario |
| Subdivision Type3: | Region |
| Subdivision Name3: | Central Ontario, Eastern Ontario |
| Subdivision Type4: | Counties |
| Source1: | Unnamed confluence |
| Source1 Location: | Stone Mills, Lennox and Addington County |
| Source1 Coordinates: | 44.5939°N -77.0328°W |
| Source1 Elevation: | 189m (620feet) |
| Mouth: | Stoco Lake |
| Mouth Location: | Tweed, Hastings County |
| Mouth Coordinates: | 44.4828°N -77.2753°W |
| Mouth Elevation: | 138m (453feet) |
| River System: | Great Lakes Basin |
| Tributaries Left: | Otter Creek |
| Tributaries Right: | Goose Creek |
The Clare River is a river that is part of the Moira River system in the Lake Ontario drainage basin in Hastings and Lennox and Addington Counties, Ontario, Canada.
The Clare River begins at the junction of several unnamed creeks in the township of Stone Mills, Lennox and Addington County at an elevation of 189m (620feet). It flows southwest into Calpin Lake at an elevation of 171m (561feet) at the community of McGuire Settlement, then continues southwest under Highway 41. It then turns west and passes into the municipality of Tweed, Hastings County. It takes in the left tributary Goose Creek and right tributary Otter Creek, flows past the settlement of Bogart, and empties into the east side of Stoco Lake on the Moira River at an elevation of 138m (453feet). The Moira River flows into the Bay of Quinte on Lake Ontario at Belleville.