| Belhavel Lough | |
| Pushpin Map: | Island of Ireland |
| Pushpin Map Alt: | Belhavel Lough location in Ireland |
| Pushpin Label Position: | none |
| Pushpin Map Caption: | Location in Ireland |
| Location: | County Leitrim |
| Outflow: | Diffagher River |
| Catchment: | 22.24km2 |
| Basin Countries: | Ireland |
| Area: | 1.01km2 |
| Elevation: | 60m (200feet) |
Belhavel Lough is a freshwater lake in the northwest of Ireland. It is located in north County Leitrim near the village of Killarga.
Belhavel Lough is about 2km (01miles) south of Killarga and 5km (03miles) north of Drumkeeran. It covers an area of 1.01km2. The lake drains east into the Diffagher River, which eventually reaches Lough Allen.
The water quality was reported to be satisfactory with a mesotrophic rating, but had a "" ecological status indicating pollution, though Zebra mussel infestation was not reported. The ecology of Belhavel Lough, and other county waterways, is threatened by curly waterweed, zebra mussel, and freshwater clam invasive species.