The Connecticut Lakes are a group of lakes in northern New Hampshire, situated along the headwaters of the Connecticut River. They are accessed via the northernmost segment of U.S. Route 3 (between Pittsburg and the Canada port of entry south of Chartierville, Quebec). The lakes are located within the boundaries of Pittsburg, but are far from the town center. Connecticut Lakes State Forest adjoins them.
There are four lakes: First Connecticut Lake, Second, Third and Fourth Connecticut Lake. First Connecticut Lake is the largest. Fourth is the smallest, northernmost, and the source of the Connecticut River. The only access to this lake is via the Fourth Connecticut Lake Trail, which goes in and out of Canada. All lakes are north of the 45th parallel.