The 1973 USAC Championship Car season consisted of 16 races, beginning in College Station, Texas on April 7 and concluding in Avondale, Arizona on November 3.

Bob Criss was killed in a private test at Phoenix before he could enter another event.

The USAC National Champion was Roger McCluskey and the Indianapolis 500 winner was Gordon Johncock.

Another driver, Salt Walther, suffered serious burns surviving a crash at the start of the race.

Note: Sam Posey, Peter Revson, Mark Donohue, David Hobbs, Jerry Grant, John Cannon, Graham McRae and Bobby Allison are not eligible for points.