Born in New York, he studied drama at the University of Miami. On his return to New York he appeared in a few small off-Broadway plays. His first film roles were very small, with the exception of a large part in a pornographic film. 

His trademark sneer and slurred speech are the result of paralysis in the left side of his face, caused by birth complications. 

He did not break through until he starred in 'Rocky' in 1976, a film that he wrote and sold himself, with the provision that he would play the lead. Stallone had two Academy Award nominations for 'Rocky'. 

Unfortunately, his attempts to expand his range floundered, and he was forced to return to the Rocky franchise a number of times (1979, 1982, 1985, and 1990) to pay for the flops; he even tried his hand at directing, as well as writing, with 'Rocky II', 'III' and 'IV'. 

His other early successes were as John Rambo in 'First Blood' and its sequels. In the 1990s he had further box-office wins with a number of action movies, including 'Cliffhanger', (for which he also wrote the screenplay), 'Demolition Man' and 'Judge Dredd'.

He still sought to expand his appeal with the low-budget Cop Land (1997) and a voice role in Antz (1998), but his $15 million plus pay-cheques are still only offered for more stereotypical action roles. 

He has been married three times, to Brigitte Nielsen, Sasha Czack and Jennifer Flavin.