Route 181 is a rural state highway in northern Connecticut, running from Barkhamsted to Hartland.

The road heads north into the village of Pleasant Valley, where it briefly overlaps Route 318 across the West Branch Farmington River.

Immediately after the river crossing, it intersects with East River Road, an unsigned state highway designated as Special Service Road 482, providing access to Peoples State Forest and leading to the village of Riverton.

After 0.6 miles (0.97 km), Route 181 turns northeast to follow Center Hill Road towards the Barkhamsted Reservoir.

It continues north parallel to, but not quite along, the west side of the reservoir towards the town of Hartland, passing by Barkhamsted Center along the way.