Route 183 is a state highway in northwestern Connecticut, running from Torrington to the Massachusetts state line in Norfolk.

Route 183 begins at an intersection with Route 4 in eastern Torrington and heads north, parallel to Route 8, into Winchester. In Winchester, it continues north, then turns northwest overlap Route 44. The two routes continue to a brief triple overlap with Route 8, then turn west and northwest along the Mad River as a simple overlap. Route 183 then continues northwest along Colebrook Brook into Colebrook. In Colebrook, it heads north, overlapping the unsigned section of Route 182A before turning northwest into Norfolk. In Norfolk, it cuts across the northeast corner of town to the Massachusetts state line, continuing as MA Route 183.

A section of Route 183 in Colebrook from the Route 182 to Church Hill Road is designated as a scenic road.

The Winsted-Colebrook route, continuing north to the Massachusetts state line, was designated in 1922 as State Highway 174. In the 1932 state highway renumbering, old Highway 174 became Route 183, running from US 44 in Winchester to the state line. In 1955, it was extended south to Torrington along former SR 710 to the current southern terminus.

The entire route is in Litchfield County.