Bennett Lake straddles the border between British Columbia and Yukon Territory in northwestern Canada, with its southern portion in BC and its northern end at Carcross, Yukon. The lake sits at an elevation of approximately 642 metres (2,602 feet) and is part of the Southern Lakes chain that forms the upper reaches of the Yukon River system. Its total shoreline extends roughly 160 kilometres (100 miles), including the West Arm (about 16 kilometres long) and Millhaven Bay off the West Arm. Shores range from fine-sand beaches to rocky cliffs, with a large number of camping spots distributed along the lake.

The primary road access is at Carcross, Yukon, at the northern end of the lake. The southern end, at the ghost town of Bennett City, is accessible only by train, plane, boat, or by hiking the Chilkoot Trail. The narrow-gauge White Pass and Yukon Route Railway runs along the lake's eastern shore and offers seasonal excursions between Skagway, Alaska, and Carcross, with the option to transport canoes or kayaks for an additional fee. This makes a one-way paddle from Bennett City to Carcross a practical route, covering the full length of the lake.

Wind is the defining hazard on Bennett Lake and demands serious attention. The lake is notorious for sudden storms that can produce large waves, and paddlers have reported conditions severe enough to require abandoning canoes and walking out. Calm conditions are most reliably found in the early morning hours; afternoon winds tend to build significantly. With nearly 24 hours of daylight available in summer, paddling in the middle of the night during calm windows is a practical strategy. Ice-out timing varies by year and can extend into early June, so early-season paddlers should verify conditions before launching.

The lake carries considerable historical weight as the starting point of the water route used by tens of thousands of Klondike Gold Rush stampeders in 1897–1898. After crossing the Chilkoot Pass, prospectors built boats and rafts at Bennett City to continue north to Dawson City. The ghost town of Bennett remains on the southern shore and is a notable point of interest. Parks Canada manages campsites along the trail and at Bennett Lake, and reservations may be required depending on the season. Fishing on the lake includes lake trout and Arctic grayling, and a valid fishing licence is required for all fishing within Yukon Territory.