Cameron was born in Pembroke, Bermuda. As a young man, he joined the British Merchant Navy, and sailed mostly between New York and South America.
When the Second World War broke out he found himself stranded in London, arriving on the ship The Eastern Prince on 29 October 1939. As he himself put it in an interview for The Royal Gazette newspaper: "I arrived in London on 29 October 1939. I got involved with a young lady and you know the rest. The ship left without me, and the girl walked out too."
In 1941, a friend named Harry Crossman gave Cameron a ticket to see a revival of Chu Chin Chow at the Palace Theatre. Crossman and five other black actors had bit parts in the West End production. Cameron who was working at the kitchen of the Strand Corner House at the time, was fed up with menial jobs and asked Crossman if he could get him on the show. At first he told Cameron that all of the parts were cast, but two or three weeks later, when one of the actors did not show up, Crossman arranged a meeting with the director Robert Atkins, who cast Cameron on the spot.
According to Cameron, he had a less difficult time than other black actors because his Bermudian accent sounded American to British ears. For example, the following year, he landed a speaking role as Joseph, the chauffeur in the American play The Petrified Forest by Robert E. Sherwood.
In 1945 and 1946 he took on the role of one of the Dukes in the singing trio "The Duchess and Two Dukes", which toured with the Entertainments National Service Association (ENSA) to play to British armed forces personnel in India in 1945, and the Netherlands in 1946. In 1946 Cameron returned to Bermuda for five months but decided to return to work as an actor in the UK. He then took a job on the London stage as an understudy in the play Deep Are the Roots. Written by Arnaud d'Usseau and James Gow, this play was staged at the Wyndham's Theatre in London for six months (featuring Gordon Heath) and then went on tour. It was during this tour that Cameron first met, and worked alongside, Patrick McGoohan during a production of that play in Coventry. (In 2012, Cameron participated alongside local actors in Bermuda in a reading of Deep Are the Roots, which the Bermuda Sun described as a play "dear to Earl’s heart, for it not only gave him his first break in the West End as Britain’s first black actor, but he also met his first wife when he travelled on tour with the production.")
He understudied in Deep are the Roots with fellow understudy Ida Shepley, a well known singer. As Cameron was having problems with his diction at the time she introduced him to a very good voice coach named Amanda Ira Aldridge. Miss Aldridge was the daughter of Ira Aldridge, a legendary black Shakespearian American actor of the 19th century. Cameron's breakthrough acting role was in Pool of London, a 1951 film directed by Basil Dearden, set in post-war London involving racial prejudice, romance and a diamond robbery. He won much critical acclaim for his role in the film.
His next major film role following his work in Pool of London was in the 1955 film Simba. In this drama about the Mau Mau uprising in Kenya, Cameron played the role of Peter Karanja, a doctor trying to reconcile his admiration for Western civilisation with his Kikuyu heritage. That same year Cameron played the Mau Mau general Jeroge in Safari.
From the 1950s to the present day, Cameron has had major parts in many films, including: The Heart Within (1957), in which he played a character Victor Conway in a crime movie again set in the London docklands; and Sapphire (1959) in which he played Dr Robbins, the brother of a murdered girl; and The Message (1976) – the story of the Prophet Muhammad, where he played the King of Abyssinia.
Other film appearances have included: Tarzan the Magnificent (1960), in which he played Tate; Flame in the Streets (1961), in which he played Gabriel Gomez; Tarzan's Three Challenges (1963), in which he played Mang; Guns at Batasi (1964), in which he played Captain Abraham; and Battle Beneath the Earth (1967), in which he played Sergeant Seth Hawkins; A Warm December (1973), in which he acted with Sidney Poitier and played the part of an African ambassador to the UK.
Cameron was strongly considered for the role of Quarrel in Dr. No (1962) by both director Terence Young and co-producer Albert R. Broccoli, whom he knew from his Warwick Films work; however, Harry Saltzman did not think him suitable for the role and cast American John Kitzmiller. They asked Cameron back to the James Bond series for Thunderball (1965), in which he played Bond's Caribbean assistant Pinder. Cameron also acted alongside Thunderball lead Sean Connery in Cuba, in which he played Colonel Levya.
His most recent film appearances include a major role in The Interpreter (2005), playing the fictitious dictator Edmond Zuwanie. Cameron's performance was universally praised. The Baltimore Sun wrote: "Earl Cameron is magnificent as the slimy old fraud of a dictator..." and Rolling Stone described his appearance as "subtle and menacing". Philip French in The Observer referred to "that fine Caribbean actor Earl Cameron". In 2006 he appeared in a cameo as a portrait artist in the film The Queen (directed by Stephen Frears), alongside Helen Mirren. In 2010 he appeared as "Elderly Bald Man" in the film Inception. In 2013 he appeared as "Grandad" in the short film Up on the Roof.
Cameron has had roles in a wide range of TV shows but one of his earliest major roles was a starring part in the BBC 1960 TV drama The Dark Man, in which he played a West Indian cab driver in the UK. The show examined the reactions and prejudices he faced in his work. In 1956 he had a smaller part in another BBC drama exploring racism in the workplace, A Man From The Sun, in which he appeared as community leader Joseph Brent, the cast also featuring Errol John, Cy Grant, Colin Douglas and Nadia Cattouse.
Cameron appeared in a range of popular television shows including series Danger Man (Secret Agent in the US) alongside series star Patrick McGoohan. Cameron worked with McGoohan again in 1967 when he appeared in the TV series The Prisoner as the Haitian supervisor in the episode "The Schizoid Man".
His other television work includes Emergency – Ward 10, The Zoo Gang, Crown Court (two different stories, each three episodes long, in 1973), Jackanory (a BBC children's series in which he read five of the Brer Rabbit stories in 1971), Dixon of Dock Green, Doctor Who – The Tenth Planet, Neverwhere, Waking the Dead, Kavanagh QC, Babyfather, EastEnders (a small role as a Mr Lambert), Dalziel and Pascoe, and Lovejoy.
He also appeared in a number of other one-off TV dramas, including: Television Playhouse (1957); A World Inside BBC (1962); ITV Play of the Week (two stories – The Gentle Assassin (1962) and I Can Walk Where I Like Can't I? (1964); the BBC's Wind Versus Polygamy (1968); ITV's A Fear of Strangers (1964), in which he played Ramsay, a black saxophonist and small-time criminal who is detained by the police on suspicion of murder and is also racially abused by a Chief Inspector Dyke (played by Stanley Baker); Festival: the Respectful Prostitute (1964); ITV Play of the Week – The Death of Bessie Smith (1965); Theatre 625: The Minister (1965); The Great Kandinsky (1994); and two episodes of Thirty-Minute Theatre (Anything You Say 1969 and another in 1971). In 1996 he appeared on BBC2 as The Abbott in Neverwhere, an urban fantasy television series by Neil Gaiman.
Following the death of Olaf Pooley on 14 July 2015, Cameron became the oldest living actor to have appeared in Doctor Who. On 8 August, 2017, he became the third "Doctor Who" actor to reach the age of 100.
Since 1963 Cameron is a practitioner of Bahá'í. The Bahá'í community held a reception in London in 2007 to honour his 90th birthday. He currently lives in Warwickshire in England. He is married to Barbara Cameron. His first wife, Audrey Cameron, died in 1994. He has six children.
He was appointed Commander of the Order of the British Empire (CBE) in the 2009 New Year Honours.
The Earl Cameron Theatre in Hamilton, Bermuda was named in his honour at a ceremony he attended there in December 2012.
The University of Warwick awarded Cameron an honorary doctorate in January 2013.