Lough Ennell is a glacial lake located approximately 3 miles south of Mullingar in County Westmeath, Ireland, beside the N52 Mullingar–Kilbeggan road. The lake measures 6.5 km long by 2 km wide, covering a surface area of roughly 11.56 km², with a maximum depth of 30 m (98 ft). A defining characteristic of the lake is its extensive shallow water: nearly two-thirds of its area is less than 8 m (25 ft) deep, and almost half is under 3 m (10 ft). This shallow profile shapes the paddling experience considerably, making much of the lake accessible and relatively calm in settled conditions, though shallow water can also be affected more readily by wind chop.

The lake is part of the Lough Ennell Special Protection Area and is designated as a Ramsar Wetland (designated 7 June 1996), reflecting its ecological importance. It supports a notably large swan population, and kayaking in the area has prompted discussion among local paddlers about proximity to wildlife. The River Brosna serves as both the primary inflow and outflow.

Lilliput Adventure Centre, located within Jonathan Swift Park on the lakeshore near Castletown Geoghegan, offers canoeing and kayaking courses, equipment hire, and accommodation for up to 50 people, along with camping facilities. This makes it a practical base for paddlers. Bloomfield House Hotel also sits on the lakeshore and provides boat hire facilities. The loughside additionally has a caravan and camping park, hotels, and restaurants.

Belvedere House, managed by the county council, is a notable landmark on the lake's shores and hosts sporting and cultural events including triathlons. The lake is well regarded for brown trout and pike fishing, and the fishery is managed by the Shannon Regional Fisheries Board's Midland Fisheries Group — paddlers should be aware of angling activity, particularly during the trout season which opens in March, with peak activity through May, June, and July.

The lake sits at a surface elevation of 81 m (266 ft) and has a catchment area of 117.62 km². Its midland location, roughly one hour's drive from Dublin, makes it a accessible destination for day trips from the east of Ireland.