Surprise Lake is a freshwater body of the southeastern portion of Eeyou Istchee James Bay (municipality), in the administrative region of Nord-du-Québec, in the province of Quebec, in Canada.

The "Surprise Lake" straddles the townships of Druillettes, Langloiserie, Hazeur and Pambrun, on the territory of the Eeyou Istchee James Bay (municipality) regional government, south of Chapais, Quebec.

Formed by a widening of the Opawica River, the "Surprise Lake" is rather deformed, with an archipelago of islands in the northwest, numerous bays and peninsulas.

Another peninsula attached to the eastern shore, i.e. south of the Opawica River, stretches over 5.7 kilometres (3.5 mi) towards southwestern of the lake, either in parallel to the current.

The origin of this toponymic designation may have been attributed to the surprise effect of the first travelers who used to ride in canoes this complex body of water to explore it as well as upstream streams.