The 2003 Toyota Atlantic Championship season was contested over 12 rounds.

In this one-make formula all drivers had to utilize Swift chassis and Toyota engines.

The Toyota Atlantic Championship Presented by Yokohama Drivers' Champion was A. J. Allmendinger driving for RuSPORT.

Lower placed drivers did not award points.

Note: Race 3 no additional point for the qualifying were awarded due to rain, starting lineup based on combined practice times.