Maligne Lake is approximately 22.5 km (14 mi) long and is 97 m (318 ft) at its deepest point. It averages 35 m (115 ft) in depth. It sits at approximately 1,670 m (5,479 ft) asl. It boasts a resident self sustaining population of rainbow trout and brook trout.
Maligne lake is fed and drained by the Maligne River, which enters the lake on its south side, near Mount Unwin. The Maligne River drains the lake from its northern end. Maligne Lake, as well as Maligne River, Maligne Mountain, and Maligne Pass, takes its name from the French word for malignant or wicked. It is theorised that an early French voyageur created this name in reference to the current of the Maligne River near its confluence with the Athabasca River.