The 1983–84 USAC Championship Car season consisted of two races, beginning in Du Quoin, Illinois, on September 5, 1983, and concluding in Speedway, Indiana, on May 27, 1984.

The USAC National Champion and Indianapolis 500 winner was Rick Mears.

This was the last year that the Championship comprised more than one race, and the Ted Horn Memorial was the last ever Indycar race on a dirt or clay surface.

By this time, the preeminent national championship season was instead sanctioned by CART.

Note: Drivers not entered for the Indianapolis 500 were not eligible for points.