The River Annalee (Irish: Abhainn na hEoghancha) flows through County Cavan in Ireland, originating at Lough Sillan near Shercock and running approximately 67 kilometres westward before joining the River Erne, which ultimately drains to the Atlantic Ocean. The river passes through Lough Tacker and runs south of Cootehill before reaching Butlersbridge, after which it flows through a series of lakes on its way to the Erne confluence. The total catchment basin covers 522 square kilometres.

One documented paddling route runs from Cootehill downstream to Killykeen, a stretch that takes in the river's mid-section and the lake systems to the west of Butlersbridge. This section reflects the river's general character: a lowland agricultural river moving through open countryside and interconnected lakelands in the Upper Erne system.

The Annalee is well regarded as a fishery, with brown trout, perch, pike, roach, and bream present throughout the river. Trout fishing is particularly noted in the upper reaches, with fish reported to two or three pounds in weight, and the stretch below Knappagh Bridge upstream of Cootehill and the area near Deredis at Butlersbridge are recognised as productive angling locations. Paddlers should be aware that fishing activity is common along the river, particularly in these areas. The river has previously hosted national fly-fishing championships, indicating that angling pressure can be significant at times.

The main tributaries joining the Annalee include the Bunnoe, Laragh, Dromore, Knappagh, Madabawn, and Cavan Rivers, primarily entering below Cootehill, which may affect water levels and flow character in the lower sections of the river.