Reginald Donald Whittington is an American former racing driver from Lubbock, Texas, who won the 1979 24 Hours of Le Mans together with his brother Bill Whittington and Klaus Ludwig in a Porsche 935, although Ludwig, a multiple winner at Le Mans and elsewhere, did most of the driving in the heavy rain as the brothers did not have any real racing experience prior to the late 1970s. Don's brother Dale also competed in open wheel racing. His father, Don Whittington, Sr. was also an American racing driver in the USAC National Championship from 1957 to 1959.

The 1979 24 Hours of Le Mans was the 47th Grand Prix of Endurance, and took place on 9 and 10 June 1979. With no other major works cars this year, the Porsche team were the strong favourites to win. Their competition would be from Cosworth-powered Mirages and Rondeaus and a swarm of Group 5 and IMSA-class Porsche 935s. The other big talking point was the presence of Hollywood actor Paul Newman, driving for Dick Barbour Racing.