Isbister Lake is a lake in the Canadian province of Saskatchewan. It is situated in the east-central part of the province along the course of Midnight Creek in the Porcupine Hills and Porcupine Provincial Forest. The lake is in the Woody River Block of Porcupine Hills Provincial Park. Highway 980 provides access to the southern shore of the lake and its amenities. Isbister Lake is situated in boreal forest surrounded by hills, other small lakes, and muskeg.