Tim Twietmeyer (born November 30, 1958) is an Auburn, California-based ultramarathon runner and an engineering manager at Hewlett Packard, in Roseville in the U.S.
state of California.
Twietmeyer is also an accomplished mountain biker, road cyclist, and retired almost-scratch golfer and swimmer.
He is best known for his five victories and unprecedented 25 sub-24 hour finishes at the 100-mile (160 km) Western States Endurance Run.