| Johnston Channel | |
| Pushpin Map: | Canada Southern Ontario |
| Pushpin Map Caption: | Location of the mouth of the Johnston Channel in Southern Ontario |
| Pushpin Map Alt: | Map of Southern Ontario with a dot at the location of the mouth of the Johnston Channel |
| Subdivision Type1: | Country |
| Subdivision Name1: | Canada |
| Subdivision Type2: | Province |
| Subdivision Name2: | Ontario |
| Subdivision Type3: | Region |
| Subdivision Name3: | Southwestern Ontario |
| Subdivision Type4: | County |
| Subdivision Name4: | Lambton |
| Source1: | Chenail Ecarté (The Snye) |
| Source1 Coordinates: | 42.5817°N -82.4461°W |
| Source1 Elevation: | 175m (574feet)[1] |
| Mouth: | Lake St. Clair |
| Mouth Coordinates: | 42.4975°N -82.4965°W |
| Mouth Elevation: | 175m (574feet) |
| River System: | Great Lakes Basin |
The Johnston Channel is a river geographically in Lambton County and on the territory of the Walpole Island 46 reserve of the Walpole Island First Nation, in Southwestern Ontario, Canada.[2] [3] [4] It is a right distributary of the Chenail Ecarté (The Snye), and like that river also flows to Lake St. Clair; thus, it is part of the Great Lakes Basin. The river also separates Walpole Island to the west (right bank) from St. Anne Island to the east (left bank), which both are part of the Walpole Island 46 reserve of the Walpole Island First Nation.
The creek begins at the right bank of the Chenail Ecarté (The Snye) at an elevation of, west of the community of Wallaceburg. It meanders south, then turns southwest, and reaches its mouth at Johnston Bay on Lake St. Clair, at an elevation of . Lake St. Clair flows via the Detroit River to Lake Erie.