William Prietzel (born September 8, 1952) is an American racing driver from Richfield, Wisconsin.

[2] He built a late model for an open rules show that was nicknamed the Franklin Flyer; the car featured large wings and it set the track record at Hales Corners.

[2] In a 2015 interview in Hot Rod magazine, he quoted as saying "The Mid-Am deal looked like an affordable way to go to a bunch of race tracks and have fun.

[2] Prietzel raced in the Trans-Am 2 (TA2) class of the Sports Car Club of America (SCCA) when it began being awarded points in 2011.

[2] The Hall of Fame cited his Hales Corner Speedway championship, participation at several area dirt tracks in Sportsman and Late Model cars, Mid American championships, and racing in NASCAR / SCCA.