Official Box Score
Ninth Indianapolis 500-Mile Race at the Indianapolis Motor Speedway
Monday, May 30, 1921
| FP | SP | Car No. | Driver | Car Name | Cassis/Engine | Laps | Status | Prize Money | |
| 1 | 20 | 2 | Tommy Milton | Frontenac | Frontenac/Frontenac | 200 | 89.621 | $26,200.00 | |
| 2 | 2 | 6 | Roscoe Sarles | Duesenberg Straight 8 | Duesenberg/Duesenberg | 200 | 88.608 | $10,100.00 | |
| 3 | 8 | 23 | R | Percy Ford* | Chicago Frontenac | Frontenac/Frontenac | 200 | 85.025 | $5,000.00 |
| 4 | 9 | 5 | R | Eddie Miller* | Duesenberg Straight 8 | Duesenberg/Duesenberg | 200 | 84.646 | $3,500.00 |
| 5 | 13 | 16 | Ora Haibe | Sunbeam | Sunbeam/Sunbeam | 200 | 84.277 | $3,000.00 | |
| 6 | 14 | 9 | Albert Guyot* | Duesenberg Straight 8 | Duesenberg/Duesenberg | 200 | 83.035 | $2,000.00 | |
| 7 | 10 | 3 | Ira Vail | Leach | Leach/Miller | 200 | 80.152 | $1,800.00 | |
| 8 | 15 | 21 | Bennett Hill* | Duesenberg Straight 8 | Duesenberg/Duesenberg | 200 | 79.132 | $1,600.00 | |
| 9 | 21 | 8 | Ralph Mulford | Frontenac | Frontenac/Frontenac | 177 | Running | $1,500.00 | |
| 10 | 17 | 15 | W | Rene Thomas | Sunbeam | Sunbeam/Sunbeam | 144 | Water hose | $0.00 |
| 11 | 18 | 27 | Tom Alley | Frontenac | Frontenac/Frontenac | 133 | Rod | $0.00 | |
| 12 | 1 | 4 | W | Ralph DePalma | Ballot | Ballot/Ballot | 112 | Rod | $10,600.00 |
| 13 | 4 | 1 | Eddie Hearne | Revere | Duesenberg/Duesenberg | 111 | Oil line | $0.00 | |
| 14 | 19 | 24 | Jimmy Murphy* | Duesenberg Straight 8 | Duesenberg/Duesenberg | 107 | Accident | $0.00 | |
| 15 | 16 | 17 | R | Riley Brett* | Junior | Brett/Brett | 91 | Accident | $0.00 |
| 16 | 23 | 28 | R | C.W. Van Ranst | Frontenac | Frontenac/Frontenac | 87 | Water hose | $0.00 |
| 17 | 3 | 7 | Joe Boyer | Duesenberg Straight 8 | Duesenberg/Duesenberg | 74 | Rear axle | $0.00 | |
| 18 | 6 | 19 | Jean Chassagne | Peugeot | Peugeot/Peugeot | 65 | Lost hood | $0.00 | |
| 19 | 5 | 22 | R | Jules Ellingboe | Frontenac | Frontenac/Frontenac | 49 | Steering | $0.00 |
| 20 | 11 | 14 | Andre Boillot | Talbot-Darracq | Sunbeam/Sunbeam | 41 | Bearing | $0.00 | |
| 21 | 7 | 18 | R | Louis Fontaine | Junior | Brett/Brett | 33 | Accident | $0.00 |
| 22 | 22 | 25 | Joe Thomas | Duesenberg Straight 8 | Duesenberg/Duesenberg | 24 | Accident | $0.00 | |
| 23 | 12 | 10 | W | Howdy Wilcox | Peugeot | Peugeot/Peugeot | 22 | Rod | $0.00 |
| Total Purse $65,300.00 | |||||||||
Time of Race: 5:34:44.65 Average Speed: 89.621 mph Margin of Victory: 3:49.38
Poll: #4 Ralph DePalma (100.750, 5:57.34) Fastest Race Lap: N/A
Winning Car Owner: Louis Chevrolet Winning Chief Mechanic: Henry Franck ** Winning Tire: Firestone
Legend: R=Indianapolis 500-Mile Race Rookie; W=Indianapolis 500-Mile Race Former Winner; *=Had Relief Help
**=Also Riding Mechanic
Lap Leaders: DePalma 1, Boyer 2, DePalma 3-5, Sarles 6, DePalma 7-110, Milton 111-200.
Lap Leader Summary: DePalma 3 times for 108 laps, Milton 1-90, Boyer 1-1, Sarles 1-1
Lead Changes: 5 among 4 drivers.