Lon Haldeman is an American ultramarathon cyclist. Nicknamed "Marathon Lon", He was the catalyst for ultra distance bicycle racing. His first achievement was in 1979 when he won the Wisconsin End to End Record covering 407 miles in 23 hours 7 minutes. In the 1982 Great American Bike Race, later renamed the Race Across America, he completely changed the parameters, cycling for 9 days and 20 hours with three other cycling pioneers John Howard, John Marino and Michael Shermer.
In 2007, the Lon Haldeman Award was created to recognise the Race Across America team that raises the most charitable donations that year.