1940 AAA Championship Car season
The 1940 AAA Championship Car season consisted of three races, beginning in Speedway, Indiana on May 30 and concluding in Syracuse, New York on September 2. There was also one non-championship event in Langhorne, Pennsylvania. The AAA National Champion was Rex Mays and the Indianapolis 500 winner was Wilbur Shaw.
Schedule and results
All races running on Paved/Dirt Oval.| Rnd | Date | Race Name | Track | Location | Type | Pole Position | Winning Driver |
| 1 | May 30 |  International 500 Mile Sweepstakes | Indianapolis Motor Speedway | Speedway, Indiana | Paved | Rex Mays | Wilbur Shaw |
| NC | June 16 | Langhorne 100 | Langhorne Speedway | Langhorne, Pennsylvania | Dirt | Tony Willman | Duke Nalon |
| 2 | August 24 | Springfield 100 | Illinois State Fairgrounds | Springfield, Illinois | Dirt | Rex Mays | Rex Mays |
| 3 | September 2 | Syracuse 100 | New York State Fairgrounds | Syracuse, New York | Dirt | Rex Mays | Rex Mays |
Leading National Championship standings
| # | Driver | Team | Points |
| 1 | Rex Mays | Bowes Seal Fast | 1225 |
| 2 | Wilbur Shaw | Boyle | 1000 |
| 3 | Mauri Rose | Elgin Piston Pin | 675 |
| 4 | Ted Horn | Ted Horn Engineering | 625 |
| 5 | Joel Thorne | Thorne Engineering | 450 |