Williston Lake, large reservoir in British Columbia, Canada

Williston Lake is a large reservoir in British Columbia and among the largest by surface area in the province. The lake was created when the W. A. C. Bennett Dam was built in the late 1960s and receives water from multiple rivers including the Peace, Parsnip, and Finlay, which form three main reaches.

The lake was formed in the late 1960s with the construction of the W. A. C. Bennett Dam as part of a large hydroelectric power project. The dam's completion fundamentally altered the landscape and flooded the traditional territory of the Tsay Keh Dene First Nation.

The reservoir was named after Ray Gillis Williston, then Minister of Lands, Forests and Water Resources. During planning it was called Peace River Reservoir. The lake flooded the territory and homes of the Tsay Keh Dene First Nation, whose homeland lay in the upper Peace basin.

The lake is best reached by car and has several boat launch points and access for kayaks. The warmer months offer the best conditions for water activities and exploring the shoreline.

The reservoir's name honours Ray Gillis Williston, then Minister of Lands, Forests and Water Resources; during planning it was called the Peace River Reservoir. It is the seventh largest reservoir in the world by volume and the largest lake in British Columbia, covering 1,761 km2. A floating island was discovered on the reservoir in 2026.