Yes, the three-time Formula 1 champion Sir Jackie Stewart competed in the Indy 500. Twice actually (1966-1967). This is the car he used in 1966, when he nearly won the race.
Stewart moved into the lead on lap 151 of 200. He stayed in first until lap 190, when his oil scavenger pump failed. His teammate and fellow rookie Graham Hill won the race, but Stewart earned the Rookie of the Year honors.
Later that year, in a non-championship race at Fuji Speedway, Stewart used this Lola to win the event, beating Bobby Unser, the only other driver on the lead lap.
Find this 1966 Lola T90 Ford Indy Car for auction at Mecum.