The Saugatuck River is a 23.7-mile-long (38.1 km) river in southwestern Connecticut in the United States. It drains part of suburban and rural Fairfield County west of Bridgeport, emptying into Long Island Sound.The Saugatuck River issues from Sugar Hollow Pond approximately 3 miles (5 km) southwest of downtown Danbury. It flows generally southeast, passing through the Saugatuck Reservoir (283 feet (86 m) above sea level), then turns south-southwest.
In Westport, it broadens into a navigable estuary along its lower 5 miles (8 km) and enters Long Island Sound approximately 4 miles (6 km) southeast of Norwalk. Interstate 95 crosses the river near its mouth downstream from Westport center. The river is wadeable along much of its course and is a popular seasonal destination for trout fishing.