Route 254 is a state highway in northwestern Connecticut running from Thomaston to Litchfield.

Route 254 then continues north along South Main Street towards Thomaston center.

In the town center, Route 254 then turns northwest along Northfield Road.

[1] The section of Route 254 from Camp Hill Road in the village of Northfield to the northern terminus in Litchfield borough is designated as a state scenic road.

In 1967, Route 254 was extended southward along South Main Street (former US 6) to the north end of SR 848.