Kingsmere Lake is a large, clear-water lake entirely within Prince Albert National Park in central Saskatchewan. At approximately 5,913 hectares (14,611 acres) in size and over 45 metres (148 ft) deep, it sits within the Waskesiu Upland and drains southward via the Kingsmere River into Waskesiu Lake, forming part of the Churchill River drainage basin. The shoreline alternates between sandy beaches, spruce-fringed headlands, and rocky points, with dense boreal forest of white spruce and paper birch throughout. The water is notably clear, with paddlers reporting the ability to see the lake bottom while suspended some six metres above it.

Access is from the Kingsmere River boat launch at the end of Kingsmere Road, a gravel road approximately 30 km from the town of Waskesiu. The parking area includes an outhouse. From the launch, paddlers travel up the Kingsmere River a short distance to a rail-car portage of roughly 800 metres to 1 kilometre that bypasses rapids at the river's head and delivers paddlers to the southern end of the lake. This portage uses steel carts on rails for transporting gear. The southern end of the lake near the Southend campground is very shallow and sandy.

Because the lake is large with wide-open stretches of water, wind and weather can create significant hazards. Paddlers should monitor conditions carefully and be prepared to wait out poor weather before crossing open sections. The paddling season runs from June through September.

Motors are permitted on the lake but are restricted to 40 HP or less. Personal watercraft such as Jet Skis and Sea-Doos are prohibited on all park waters. As of April 15, 2025, all watercraft require an Aquatic Invasive Species (AIS) Certification Permit before entering park waters. Overnight campers must register at the Prince Albert National Park Visitor Centre on the day of their trip and obtain a backcountry camping permit. A Parks Canada park pass is also required.

Seven backcountry campgrounds are accessible from the lake, some reachable only by water. The Bagwa Canoe Route, approximately 25 km for the loop, connects Kingsmere Lake with Clare, Lily, and Bagwa Lakes via three portages — the Clare Lake portage is notably muddy. A longer option of roughly 33 km includes the North End campground at the lake's northern tip, from which a 3 km trail leads to Grey Owl's Cabin on Ajawaan Lake. The Grey Owl Trail, 19.9 km long, follows the eastern shore of Kingsmere Lake. Fish species present include lake trout, walleye, and northern pike. Wildlife along the route includes blue-winged teal, great blue heron, loons, Red-necked Grebes, and beaver.