He was born in Balcarce, Argentina. He began his racing career in South America in 1934, mostly in long distance road races and he was Argentine National Champion in 1940 and 1941. The outbreak of World War II halted his rise and he did not begin racing in Europe until 1947.
Initially he was not particularly successful until racing a Alfa Romeo in 1950. He came second in the championship in 1950 and won his first title in 1951. He was competing well in 1952 in a Maserati until a serious accident at Monza, Italy ended his season. In 1954 he won his second title with Mercedes, winning eight out of twelve races (six out of eight in the championship). He won again with Mercedes the following year, but in 1955 the company withdrew from all racing following the disaster at Le Mans in which 81 spectators were killed.
Fangio moved to Ferrari, replacing Alberto Ascari who had been killed in an accident, winning his fourth title - finishing first in three races and second in all the other championship races. In 1957 he returned to Maserati and won his fifth title, notable for an extraordinary performance to win at the Nurburgring in Germany. After his series of back-to-back championships he retired in 1958, after the French Grand Prix, having won 24 Grand Prix in 51 starts.
He died on July 17, 1995 and is buried in La Recoleta Cemetery, Buenos Aires, Argentina.