Michael Caine was born as Maurice Joseph Micklewhite in London, to Ellen (née Burchell), a cook, and Maurice Micklewhite Sr., a fish-market porter. He had a younger brother, Stanley Caine, and an older maternal half-brother named David Burchell. He left school at age 15 and took a series of working-class jobs before joining the British army and serving in Korea during the Korean War, where he saw combat. Upon his return to England, he gravitated toward the theater and got a job as an assistant stage manager. He adopted the name of Caine on the advice of his agent, taking it from a marquee that advertised The Caine Mutiny (1954). In the years that followed, he worked in more than 100 television dramas, with repertory companies throughout England and eventually in the stage hit "The Long and the Short and the Tall".

Zulu (1964), the epic retelling of a historic 19th-century battle in South Africa between British soldiers and Zulu warriors, brought Caine to international attention. Instead of being typecast as a low-ranking Cockney soldier, he played a snobbish, aristocratic officer. Although "Zulu" was a major success, it was the role of Harry Palmer in The Ipcress File (1965) and the title role in Alfie (1966) that made Caine a star of the first magnitude. He epitomized the new breed of actor in mid-1960s England, the working-class bloke with glasses and a down-home accent. However, after initially starring in some excellent films, particularly in the 1960s, including Gambit (1966), Funeral in Berlin (1966), Play Dirty (1969), Battle of Britain (1969), Too Late the Hero (1970), The Last Valley (1971) and especially Get Carter (1971), he seemed to take on roles in below-average films, simply for the money he could by then command.

However, there were some gems amongst the dross. He gave a magnificent performance opposite Sean Connery in The Man Who Would Be King (1975) and turned in a solid one as a German colonel in The Eagle Has Landed (1976). Educating Rita (1983), Blame It on Rio (1984) and Hannah and Her Sisters (1986) (for which he won his first Oscar) were highlights of the 1980s, while more recently Little Voice (1998), The Cider House Rules (1999) (his second Oscar) and Last Orders (2001) have been widely acclaimed. Caine played Nigel Powers in the parody sequel Austin Powers in Goldmember (2002), and Alfred Pennyworth in Christopher Nolan's Dark Knight trilogy. He appeared in several other of Nolan's films including The Prestige (2006), Inception (2010) and Interstellar (2014). He also appeared as a supporting character in Alfonso Cuarón's Children of Men (2006) and Pixar's sequel Cars 2 (2011).

As of 2015, films in which Caine has starred have grossed over $7.4 billion worldwide. He is ranked the ninth highest grossing box office star. Caine is one of several actors nominated for an Academy Award for acting every decade from five consecutive decades (the other being Laurence Olivier and Meryl Streep). He was appointed Commander of the Order of the British Empire in the 1992 Birthday Honours, and was knighted by Queen Elizabeth II in the 2000 Birthday Honours in recognition for his contributions to the cinema.

Caine has been married twice. First to actress Patricia Haines from 1954 to 1958. They had a daughter, Dominique, in 1957. A bachelor for some dozen-plus years after the divorce, he was romantically linked to Edina Ronay (for three years), Elizabeth Ercy, Nancy Sinatra, Natalie Wood, Candice Bergen, Bianca Jagger, Françoise Pascal and Jill St. John. In 1971 he met his second wife, fashion model Shakira Caine (née Baksh), and they married in 1973, six months before their daughter Natasha was born. The couple has three grandchildren, and in 2023, they celebrated their 50th wedding anniversary.