The Naugatuck Trail is a 6.8-mile (10.9 km) Blue-Blazed hiking trail "system" in the eastern central-lower Naugatuck River Valley in New Haven County, Connecticut, USA. It is almost entirely contained in the . The mainline (officially the "Blue" or "non-dot") trail is primarily east to west with three short side or spur trails. Composed of four trails (including the primarily East-to-West mainline trail (5.5 miles) plus three shorter side trails), at its western end the trail ends with a section alongside Route 8 and the Naugatuck River. During the 1930s and 1940s, it was much larger. But post–World War II housing developments of the Connecticut Blue-Blazed Trails, led to its drastic reduction.