The 35th International 500-Mile Sweepstakes was held at the Indianapolis Motor Speedway on Wednesday, May 30, 1951. The event was part of the 1951 AAA National Championship Trail, and was also race 2 of 8 in the 1951 World Championship of Drivers. For the second year in a row, no European Formula One-based teams entered the race.

Dennis Clayton "Duke" Nalon was an American racing driver. He competed in midget car, sprint car, and Indy car races. Nicknamed "The Iron Duke," Nalon was part of the "Chicago Gang" along with Tony Bettenhausen and others. These racers toured tracks in the Midwest and East Coast of the United States.