Whitemouth Lake is a large but shallow freshwater lake located in the Sunrise Corner region of Manitoba, Canada. Its shallow depth makes it well-suited for canoeing and kayaking, offering a relatively calm paddling environment. The lake has a public boat ramp available for access, with coordinates approximately 49.242436, -95.682633.

One of the most notable features in the area is the Whitemouth Island Ecological Reserve, situated within or adjacent to the lake. This reserve represents the westernmost example of a largely undisturbed deciduous forest of the St. Lawrence–Great Lakes region in Canada, and contains eight species of eastern deciduous plants considered rare in Manitoba. Paddlers with an interest in natural history and ecology will find this reserve a significant point of interest.

The lake is historically associated with walleye fishing, though in recent years the shallow water has made the fish population susceptible to winter die-offs, which may affect the overall ecological character of the lake. The shallow nature of the water is worth keeping in mind when planning a trip, as it can influence conditions throughout the year.

Whitemouth Lake also serves as the headwaters of the Whitemouth River, which flows through Northwest Angle Provincial Forest and Sandilands Provincial Forest before joining the Winnipeg River near Seven Sisters Rapids. Paddlers interested in extending their trip can connect to this river route, though the Whitemouth River is noted as a whitewater river and travel without detailed information on its hazards is not recommended. A canoe route guide covering the full Whitemouth Lake to Winnipeg River corridor has been published by the Manitoba Department of Natural Resources, Parks Branch, authored by Réal Bérard, and is available for purchase.

The lake's shallow character and calm water make it accessible for paddlers of varying experience levels, and the surrounding environment provides opportunities to observe birds, ducks, and turtles along the shoreline.