| 1921 AAA Championship Car season | |
|---|---|
| AAA National Championship Trail | |
| Season | |
| Races | 20 |
| Start date | February 27 |
| End date | December 11 |
| Awards | |
| National champion |  Tommy Milton |
| Indianapolis 500 winner | Tommy Milton |
The 1921 AAA Championship Car season consisted of 20 races, beginning in Beverly Hills, California on February 27 and concluding in San Carlos, California on December 11. There was also one non-championship race. The AAA National Champion and Indianapolis 500 winner was Tommy Milton.
Alton Soules, and his riding mechanic Harry Barner, perished at the Fresno Speedway during the second race.