Fangio was born in Balcarce, a small town near Mar del Plata in the Buenos Aires province of Argentina, to a family of Italian immigrant descent. His grandfather Giuseppe had emigrated from the Abruzzo region of Italy in 1887. Fangio left school at 13 to work as a mechanic, and never returned. He developed pneumonia in his youth after playing football and was bedridden for two months before recovering.
He began racing in Argentina in 1936, driving a rebuilt 1929 Ford Model A. By 1940 he was competing in the Turismo Carretera, Argentina's gruelling open-road stock car series, and won the Argentine National Championship in both 1940 and 1941. The 1940 Gran Premio del Norte covered nearly 10,000 kilometres through Argentina, Bolivia, and Peru — a 15-day ordeal through deserts, jungles, and Andean passes at altitudes above 4,000 metres. Fangio won it despite multiple mechanical setbacks including a damaged driveshaft, a punctured radiator, and headlights falling off in darkness.
A personal catastrophe struck during the 1948 South American Grand Prix, a 9,580-kilometre rally from Buenos Aires to Caracas. Driving in thick fog near the Peruvian coast at night, Fangio approached a bend too fast and crashed. His co-driver Daniel Urrutia, 35, was thrown through the windscreen and died of his injuries. Fangio, who suffered neck injuries, believed he would never race again. His performances in Argentina had attracted enough attention from the Automobile Club of Argentina and the government of Juan Perón that they purchased a Maserati and sent him to Europe to continue his career in late 1948.
Fangio made his first Formula One World Championship appearance in 1950, driving for Alfa Romeo alongside Nino Farina and Luigi Fagioli. He won three of the championship rounds but missed one with mechanical failure while Farina won the other three, giving Farina the inaugural championship. The following year Fangio took the title for Alfa Romeo, winning three races.
A serious accident at Monza in 1952 — caused by exhaustion after driving overnight through the Alps to reach the circuit following a missed connecting flight — left him with a broken neck and absent from racing for the rest of the season.
He returned to win the championship again in 1954, first with Maserati and then with Mercedes-Benz after the German team entered the season mid-year. In 1955 he took a fourth title with Mercedes, enduring a brutal Argentine Grand Prix run in 40-degree heat where the chassis burned his right leg so severely he needed three months to recover. He won despite being the only frontrunner to complete the race solo, while younger teammates drove in relays.
In 1956 Fangio moved to Ferrari, winning the title in part because teammate Peter Collins handed over his car during the final race, sharing the points that gave Fangio the championship. In 1957 he returned to Maserati for his fifth and final championship, producing what is often cited as the greatest single race drive in Formula One history: the German Grand Prix at the Nürburgring.
Running on half-tanks, Fangio led before pitting on lap 13, emerging third and 50 seconds behind the Ferraris of Collins and Mike Hawthorn following delays in the stop. With new tyres and a lighter fuel load, he proceeded to set the lap record repeatedly — on the penultimate lap his best time was eleven seconds faster than anything the Ferraris could manage. He passed both Ferraris on the last lap and won by three seconds. This performance secured his fifth championship with two races remaining and is still regarded as a defining moment in the sport's history.
Fangio retired from Formula One after the 1958 French Grand Prix, at which race leader Hawthorn briefly braked before the finish line out of respect so Fangio could complete the 50-lap distance in his final race. His parting words to his mechanic were: "It is finished."
On 23 February 1958, during practice for the Cuban Grand Prix in Havana, two gunmen from Fidel Castro's 26th of July Movement entered Fangio's hotel and kidnapped him. He was held for 29 hours and treated well by his captors, who allowed him to follow the race via radio. The Cuban government continued the race and ordered a police hunt, but the kidnappers were never caught. Fangio later said of the incident: "Well, this is one more adventure." He was released after Cuba's Batista government was embarrassed by its failure to locate him. The episode was later dramatised in a 1999 Argentine film, Operación Fangio.
After retirement, Fangio served as honorary president of Mercedes-Benz Argentina from 1987 until 1994. The Juan Manuel Fangio Technological-Cultural Center and Automobile Museum, established in Balcarce in 1986, houses the trophies and cars he donated to his hometown in 1983. A Mercedes-Benz W196R driven by Fangio in his 1954 and 1955 championship campaigns sold at auction in England in July 2013 for approximately $30 million.
Fangio's record of five championships stood until Michael Schumacher won his sixth in 2003. Schumacher observed: "Fangio is on a level much higher than I see myself. What he did stands alone." When Lewis Hamilton equalled Fangio's five titles in 2018, he called Fangio "the Godfather of our sport." In October 2020 both The Economist and a separate quantitative analysis by Carteret Analytics ranked Fangio as Formula One's greatest driver of all time. He is revered in Argentina as one of the greatest sportsmen the nation has ever produced. Six statues of Fangio, sculpted by Catalan artist Joaquim Ros Sabaté, stand at circuits and motor racing venues around the world. Fangio died on 17 July 1995 in Buenos Aires, aged 84, from bronchopneumonia.