Gordon K. "Sandy" Douglass (October 22, 1904 – February 12, 1992) was an American racer, designer, and builder of sailing dinghies.

[1]: 89–90  Douglass befriended English boat designer and racer, Uffa Fox, whom he met through sailing canoe racing.

[1]: 181–93 : 194–200  Influenced by Uffa Fox's International 14 design, and built using the innovative molded plywood technique, the Thistle quickly caught on with dinghy racers.

[2] It was light, fast, and held to strict one design standards by the Thistle Class Association, founded by Douglass.

[1]: 231–34  His goal was that it be stable and fast, and yet be family friendly, using a broader beam and harder bilges than in previous designs.

[1]: passim  His involvement with the Thistle and the Highlander ended in 1951 when he split with Ray McLeod, his business partner.

[1]: 247–56  Its wide beam and the prohibition of hiking straps were an effort to make the boat more competitive for smaller-sized people like Douglass and his wife, Mary, who crewed for him for 30 years.