State Route 204 (SR 204) is part of Maine's system of numbered state highways, located in Hancock County.

It runs from SR 3 in Trenton, passing SR 184 in Lamoine, and ending at the intersection with Seal Point and Marlboro Beach roads.

The route is 6.5 miles (10.5 km) long.

After the concurrency, SR 204 is heading southeast towards Seal Point Road and Marlboro Beach Road, where the SR 204 designation ends.

[2] The entire route is in Hancock County.