Wilhelmina "Willy" den Turk (3 April 1908 – 19 June 1937) was a Dutch swimmer. She won a gold medal in the 100 m backstroke and a silver in the 4×100 m freestyle relay at the 1927 European Aquatics Championships. The same year she set a world record in the 100 m backstroke. This was the first Dutch world record in a backstroke event, and it was bettered by another Dutch swimmer, Marie Braun.