The Suncook Lakes are a pair of lakes located in Belknap County in central New Hampshire, United States, in the town of Barnstead. Upper Suncook Lake encompasses , while Lower Suncook Lake covers . The lakes are connected by a channel, spanned by a road bridge. A dam at the outlet of Lower Suncook Lake controls the water level of both lakes. The lakes are located along the Suncook River, a tributary of the Merrimack River. There are three islands on Lower Lake.
Lower Suncook Lake has an average depth of and a maximum depth of , while Upper Suncook Lake has a greater average depth and a maximum depth greater than . The lakes are classified as a warmwater fishery, with observed species including smallmouth and largemouth bass, chain pickerel, horned pout, and white perch. Rainbow trout can be found in the deeper Upper Suncook Lake.