Route 27, also known as Main Street and Dog River Road, is a 7.5-kilometre (4.7 mi), two-lane, uncontrolled-access, secondary highway in central Prince Edward Island.

[2] The route is entirely in Queens County.

The route diverges from Route 1 at an interchange east of the community of New Haven and proceeds eastward through the Clyde River valley into Cornwall, constituting the town's main street.

The road curves northward at an intersection with Route 19 and continues through the town and farmland to the northeast.

The entire route is in Queens County.