The 1984 CART PPG Indy Car World Series season, the sixth in the CART era of U.S. open-wheel racing, consisted of 16 races, beginning in Long Beach, California on March 31 and concluding in Las Vegas, Nevada on November 10. The PPG Indy Car World Series Drivers' Champion was Mario Andretti and the Indianapolis 500 winner was Rick Mears. Rookie of the Year was Roberto Guerrero. The 68th Indianapolis 500 was sanctioned by the USAC, but counted in the CART points standings.
The following teams and drivers competed for the 1984 PPG Indy Car World Series. Number in parentheses ( ) is the number used at Indianapolis only.
This season featured a new oval in Canada called Sanair Super Speedway. Other changes included new street circuit races at the Meadowlands Sports Complex, and in Long Beach, California. Also added was a new permanent road course race at Portland International Raceway. Leaving the schedule was Riverside International Raceway and Atlanta Motor Speedway.
<nowiki>*</nowiki> The Detroit News Grand Prix was scheduled to be held on September 23, but postponed a day by rain.
Best result in each race counts towards the Nations' cup.