Michael Mario Andretti (born October 5, 1962) is an American former racing driver, and current team owner. Statistically one of the most successful drivers in the history of American open-wheel car racing, Andretti won the 1991 CART championship, and amassed 42 race victories, the most in the CART era and fifth-most all time. Since his retirement, Andretti has owned Andretti Autosport, which has won four IndyCar Series championships and five Indianapolis 500 races. He is the son of Mario Andretti, a multi-time champion, and is the father of IndyCar Series driver Marco Andretti.

Andretti was born on October 5, 1962, in Bethlehem, Pennsylvania, in the Lehigh Valley region of eastern Pennsylvania to race car driver Mario Andretti, a four-time IndyCar champion and one-time Formula One champion and his wife, Dee Ann (née Hoch). His brother Jeff Andretti competed in IndyCar. His uncle, Aldo Andretti, was an open wheel racer until an accident ended his racing career. Aldo's son John Andretti, his first cousin, raced in IndyCar before he became a NASCAR regular. He returned to IndyCar in 2007, 2008, 2009, 2010 and 2011, where he raced in the Indy 500. Aldo's other son, Adam, is also a racing driver. In 2006, his eldest son, Marco, made his debut in the IndyCar Series. The Andretti family became the first family to have five members (Michael, Mario, Marco, Jeff, and John) compete in the same series (CART/Champ Car/IndyCar).

Andretti graduated from Nazareth Area High School in Nazareth, Pennsylvania, and then attended Northampton Community College in Bethlehem.^{[citation needed]}

Following a successful career racing karts, winning fifty of his 75 races over eight years, Andretti moved into racing cars. He obtained his SCCA National License in 1980, then won six races to claim the SCCA's Northeast Division Formula Ford championship in 1981. He also drove in a number of Formula Vee races in regional SCCA events.

In 1982, Andretti won six of the eleven races on his way to winning the Robert Bosch US Formula Super Vee Championship. He also won the opening race of the 1983 Super Vee season before he moved up to drive in Formula Atlantic, and won his second title by winning the FIA Formula Mondial North American Cup the following season. Although he made his international sports car debut at the 1982 24 Hours of Le Mans, he was denied the opportunity to race, as the Mirage M12 he had chosen to race with his father was disqualified eighty minutes before the race was due to start. The father and son partnership returned to the Circuit de la Sarthe the following year, and were joined by Philippe Alliot in the Porsche Kremer Racing's Porsche 956, taking third place. Andretti also raced alongside his father in the Riverside 6 Hours where they were joined by A. J. Foyt and Preston Henn, but the Porsche 935 failed to finish. The father and son duo paired up again the 1984 24 Hours of Daytona, this time in a full-works Porsche 962, which made its race debut. They took pole position, but during the race, the engine broke.

Andretti made his CART debut in 1983, racing for the Kraco Enterprises team. He re-signed for Kraco for the 1984 season, where he managed five third-place finishes and ended his rookie season in seventh overall. In the Indianapolis 500, he finished fifth and shared the Rookie of the Year award with Roberto Guerrero. He went on to win his first IndyCar race in 1986 in the Toyota Grand Prix of Long Beach. The season became a two-man battle for the championship title, between Andretti and Bobby Rahal. Andretti would take the points lead with his victory on the Milwaukee Mile. A week later, on Father's Day, Andretti was leading on the final lap at Portland, when his March-Cosworth 86C ran out of fuel, allowing his father Mario to beat him by just 0.07 seconds. It was one of the most shocking finishes in the history of IndyCar, and the closest finish until 1997. With Rahal continuing to win races, Andretti's consistent finishing only allowed Rahal a nine-point lead in the standing with two races remaining. Andretti won a key victory in at Phoenix. Going into the season finale at Tamiami Park, Andretti was just three points behind Rahal, but neither driver were a factor in the race, with Andretti retiring with a broken halfshaft.

In a one-off race with Alfa Corse, he took part in the inaugural World Touring Car race, 500 km di Monza. Paired with Alessandro Nannini, they finished sixteenth overall, second in class. Back in CART, he continued with Kraco in 1987, and like 1986, the championship was between Andretti and Rahal. Andretti would win the 1987 Marlboro 500, drawing within nine points of Rahal. With him winning in dominating fashion at Nazareth Speedway, his championship hopes remained alive, although Rahal clinched the championship at the next race. Andretti would also win the season finale, Tamiami Park. He would finish runner-up for the second season in a row. Back in June 1987, Andretti joined Hendrick Motorsport to race a Chevrolet Corvette GTP in the Mid-Ohio 500 km, this time joined by his cousin, John Andretti, where they finished eleventh. Following Porsche's defeat in the 1988 Daytona 24 Hours, Porsche entered a 962C at Le Mans for Michael, Mario, and John. They were competitive in the first half of the race until the Andretti family's car needed minor repairs before lapsing on to five cylinders, finishing sixth overall. Michael and Mario join Busby Racing for 1989 Daytona 24 Hours, only for their 962 to retire with brakes problems.

The 1988 CART season was a lean year for Andretti. He remained with Kraco and won only a single race, the Marlboro Challenge, for which no championship points were awarded. For the 1989 season, Andretti signed with Newman/Haas Racing, partnering him with his father. He won two races that season, Molson Indy Toronto and the 1989 Marlboro 500 at the Michigan International Speedway, placing third in points. For 1990, Al Unser Jr. would become champion, Andretti was his nearest competitor, winning five races and four poles. In the second-to-last race of the season at Nazareth, Unser crashed out, giving Andretti a huge opportunity to close the gap. Andretti managed only a sixth-place finish, and could not capitalize on Unser's misfortune. Unser left Nazareth with a 27-point lead, enough to clinch the championship. Andretti would finish runner-up once again. For the 1991 24 Hours of Daytona, Andretti was joined by his brother, Jeff Andretti. Piloting a Jochen Dauer Racing entered Porsche 962, they were classified fifth overall, despite not finishing the race.