Route 188 is a state highway in west-central Connecticut, running in an "L" pattern from Seymour to Middlebury.

In Oxford, it heads northwest from its junction with the western end of Route 334 across the town before entering Southbury.

In Southbury, it heads north along the Eight Mile River, briefly overlapping with Route 67.

It then continues northeast past Waterbury-Oxford Airport to intersect I-84 at Exit 16.

[1] Route 188 was commissioned in 1935 from former unsigned state roads, running from the current southern terminus in Seymour to Old Waterbury Road (former Route 135) in Middlebury.