Kilglass Lough (Irish: Loch Chill Ghlais) is a freshwater lake in north County Roscommon, situated approximately 10 km northeast of Strokestown. The lake measures roughly 3.8 km in length and 0.9 km at its widest point, covering a surface area of 2.02 km². It sits at an elevation of 38 m and has a catchment area of 230.3 km². The lake forms part of the Strokestown Lakes system, a connected group of water bodies in the region.

Access to the water is available via a marina and boat launch area, reached by a steep, narrow single-lane road. The approach requires care, particularly for larger vehicles, though the site has been used successfully by campervans. The launch area includes picnic tables and a water tap on site. The area tends to see increased activity on summer weekends, when locals use the ramp to launch boats, but is generally quiet at other times.

The lake supports a variety of fish species including pike, bream, roach, tench, rudd, and sea trout, which means anglers are likely to share the water. Paddlers should be aware of boat traffic, particularly during warmer months when recreational boating increases.

Kilglass Lough is part of the broader Shannon Lakes area, and the nearby Shannon River Adventure centre, located close to the villages of Rooskey and Dromod, offers guided kayaking and canoeing activities that include visits to the Kilglass Lakes. This suggests the lake is considered suitable for both kayaking and open canoe paddling.

The lake's relatively modest dimensions — under 4 km long and less than 1 km wide — make it manageable for a day paddle, with the potential to explore the broader Strokestown Lakes system for those seeking a longer outing.