The Windmill is an American sailing dinghy that was designed by Clark Mills as a one-design racer and first built in 1953.

[1][3][5][6][7] The Windmill is a recreational sailboat, built predominantly of plywood or fiberglass in the form of a double hull with a foam core, resulting in an unsinkable boat.

The hull has a rounded plumb stem, a conventional transom, a transom-hung rudder controlled by a tiller and a retractable daggerboard.

It displaces 198 lb (90 kg),[1][3] The boat has a draft of 4.17 ft (1.27 m) with the daggerboard extended and 6 in (15 cm) with it retracted, allowing beaching or ground transportation on a trailer or car roof rack.

[3] In a 1994 review Richard Sherwood wrote, "the Windmill is a high-performance sloop that can be built from plans or from a kit, or purchased complete.