Born Sidney Joel Cohen on the 8th May 1913, Sid James was a South African born Jew whose parents worked in the music hall business. He worked in various professions during his 20s and thirties - these included diamond cutting, hairdressing and even boxering. In was in the Orange Free State that the met and married Berthe Sadie Delmont in 1936 and her father bought Sid a salon. Soon afterwards he announced that he wanted to become an actor and joined Johannesburg Repertory Players. Through this opening he then got work with the South African Broadcasting Corporation.

When 1939 came he was commissioned as a Lieutenant in the South African Army and soon became a producer in its entertainment unit. As such he was typical of a generation of British performers and writers who learned their trade while in the Armed Forces. After the service, James arrived in London on Christmas Day 1946 looking to make a start in acting. His grizzled face meant that he became typecast as minor gangsters in his early film appearances. His career success came when he transformed himself into a quintessential Londoner, an ordinary bloke, who drew sympathy from his audience despite playing a rascal in many of his roles.

In 1949 he played an American film director in a 30 minute play called Family Affairs . After significant supporting roles in The Lavender Hill Mob (1951) and The Ritchfield Thunderbolt (1953), his persona began to develop, from gangsters, into characters who lived just this side of the law in the austere conditions of 1950s Britain. Although he was best known for his comic roles, James rarely turned down dramatic work. His next television appearance was in Another Part of the Forest (1954) one of an acclaimed 20th Century Theatre series. 

In 1954 he began the famous comedy partnership with Tony Hancock, at first on radio, in ‘Hancock's Half Hour’, this quickly became the most popular TV comedy series in Britain. James was soon getting as many laughs as his partner, much to the discomfort of the star, who eventually had Sid dropped from the show. He never worked with Hancock again, but he was immediately contracted by the BBC to star in a Galton and Simpson-scripted series called Citizen James, (1960-62). In a series called ‘It's a Deal’ (1961), he played a working class property dealer whose business partner was a Mayfair playboy (Dennis Price). Mismatched in class, the two characters were essentially similar rogues underneath who found themselves reluctantly dependent on one another.