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 402 acres, while Lower Suncook Lake covers 295 acres. The lakes are connected by a 1,000-foot-long 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 9 feet and a maximum depth of 16 feet, while Upper Suncook Lake has a greater average depth and a maximum depth greater than 40 feet.