The 1983 CART PPG Indy Car World Series season was the 5th national championship season of American open wheel racing sanctioned by CART. The season consisted of 13 races. Al Unser, Sr. was the national champion, and the rookie of the year was Teo Fabi. The 1983 Indianapolis 500 was sanctioned by USAC, but an arrangement was made such that it counted towards the CART points championship. Tom Sneva won the Indy 500, after three previous runner-up finishes.
Al Unser, Sr. jumped out to the early points lead, with second-place finishes in the first three races of the season. Unser, Sr. finished second at Indianapolis to Tom Sneva, but not without some controversy. Rookie Al Unser, Jr. was accused of blocking for his father, but Sneva prevailed, making the winning pass with ten laps to go. Unser won at Cleveland, finished second at the Michigan 500, and third at Road America. After 6 of 13 races, Unser, Sr. had a 35-point lead over Tom Sneva in the standings.
Rookie Teo Fabi made headlines at Indianapolis, becoming the first rookie to win the pole since 1950. His car dropped out, however, with a failed fuel o-ring. After a mixed start to the year, Fabi's season came alive in July, winning his first career race at the Pocono 500. Fabi jumped from 8th in points to as high as second following his win at Mid-Ohio. Fabi began to whittle away at Unser's point lead. Unser was running consistently, and had no finish worse than 11th.
In the next-to-last race of the season at Laguna Seca, Fabi dominated. He won the pole position and led 95 of 98 laps, winning his third race of the season. With only one race to go, Unser's point lead was down to 15 points. At the season finale in Phoenix, Fabi put in another dominating performance. He won the pole and led 138 of 150 laps. Fabi's championship hopes, however, fell just short as Al Unser came home 4th. Al Unser won the title by a mere 5 points over Fabi.
Other top stories from 1983 included Newman/Haas Racing joining the series with driver Mario Andretti, and the rookie debut of Al Unser, Jr. Though Unser, Jr. did not win any races, he had ten top-10 finishes en route to 7th in points.