1981 CART PPG Indy Car World Series

The 1981 CART PPG Indy Car World Series season, the third in the CART era of U.S. open-wheel racing, consisted of 11 races, beginning in Avondale, Arizona  on March 22 and concluding at the same location on October 31. The PPG Indy Car World Series Drivers' Champion was Rick Mears despite missing Round 2 at Milwaukee due to injuries sustained in the Indianapolis 500. Rookie of the Year was Bob Lazier. After the disagreement with the USAC during the previous season, the 65th Indianapolis 500 was not part of the Series, however no competing race was scheduled and most CART teams and drivers did take part.

Drivers and constructors
The following teams and drivers competed for the 1981 CART World Series.

Notable team and driver changes

 * Tom Sneva left Jerry O'Connell Racing for new team Bignotti-Cotter Racing. The team scaled back to part-time for 1981.
 * Team Penske expanded to a three-car operation, with Bill Alsup joining. His owner-driver team Alsup Racing only ran part-time in 1981.
 * After racing a limited schedule beforehand, Tony Bettenhausen Jr. ran his first full-time season with his new owner-driver team Bettenhausen Racing.
 * Dick Simon replaced Sheldon Kinser at Leader Card Racing, leaving Kinser without a ride. Simon's old team, Vollstedt Enterprises, did not compete.
 * Mario Andretti returned to running the majority of the races after a stint in Formula One, driving for Patrick Racing. He replaced Tom Bagley, who was left without a ride.
 * Rookie driver Scott Brayton ran a full schedule with family-owned team Brayton Racing.
 * After running part-time in 1980, Machinists Union Racing ran a full schedule with driver Larry Dickson.
 * Spike Gehlhausen was replaced at Bob Fletcher Racing by rookie driver Bob Lazier.
 * Josele Garza ran his first season with family-owned team Garza Racing.
 * Steve Chassey ran his first full-time season for the Jet Engineering team.
 * AMI Racing only ran two races in 1981 after running full-time in 1980. Gary Bettenhausen was left without a full-time ride.
 * Interscope Racing also stopped running full-time, along with driver Danny Ongais.
 * At Cannon Racing, Larry Cannon only ran the first few races, with most of the rest driven by Dick Ferguson.
 * This was Bobby Unser's final season of IndyCar racing. See the 1981 Indianapolis 500 for more information.

Notable equipment changes

 * Tempero Racing switched from an Eagle to McLaren chassis.
 * Menard Racing switched from an Offenhauser to Chevrolet engine. With this shift the Cannon Racing team was the only full-time team that still used Offenhauser engines.

Schedule
Of note was the addition of the inaugural Michigan 500 to replace the California 500 at the now-closed Ontario Motor Speedway. The Tony Bettenhausen 200 at Milwaukee was originally scheduled for August 2, but was rained out and postponed until September 5.

- The Detroit News Grand Prix was supposed to run for 150 miles, but was shortened due to a scoring error. Oval/Speedway Dedicated road course

Race Results
{{legend|#fb9902|Non-championship event|border=solid 1px #AAAAAA}}

Note, the total time of the Norton Michigan 500 does not include red flag stoppage time as the race was stopped for nearly 1 hour due to a bad pit lane fire