The Thistle is an American planing sailing dinghy that was designed by Sandy Douglass as a one-design racer and first built in 1945.

[1][2][3] The design was originally built by Douglass & McLeod in the United States, but the company went out of business in 1971.

The hull has no decks, a plumb stem and transom, a transom-hung rudder controlled by a tiller and a retractable, drum-mounted centerboard.

[1][3] The boat has a draft of 4.50 ft (1.37 m) with the centerboard extended and 6 in (15 cm) with it retracted, allowing beaching or ground transportation on a trailer.

[1] For sailing the design is equipped with symmetrical spinnaker of 220 sq ft (20 m2) and built-in flotation.