Gambon was born in Cabra, Dublin, during World War II (known in Éire as The 1939-45 Emergency). His father, Edward Gambon, was an engineer, and his mother, Mary (née Hoare), was a seamstress. His father decided to seek work in the rebuilding of London, and so the family moved to Mornington Crescent in north London, when Gambon was five. His father had him made a British citizen, a decision that would later allow Gambon to receive a substantive, rather than honorary, knighthood and CBE.
Brought up as a strict Roman Catholic, he attended St Aloysius Boys' School in Somers Town and served at the altar. He then moved to St Aloysius' College in Hornsey Lane, Highgate, London, whose former pupils include Peter Sellers. He later moved to North End, Kent, and attended Crayford Secondary School, before leaving with no qualifications at fifteen. He then gained an apprenticeship with Vickers Armstrong as a toolmaker. By the time he was 21, he was a qualified engineer. He kept the job for a further year, acquiring a fascination and passion for collecting antique guns, clocks, watches and classic cars.
At age 24, Gambon wrote a letter to Micheál Mac Liammóir, the Irish theatre impresario who ran Dublin's Gate Theatre. It was accompanied by a CV describing a rich and wholly imaginary theatre career – and he was taken on.
Gambon made his professional stage début in the Gate Theatre Dublin's 1962 production of Othello, playing "Second Gentleman", followed by a European tour. A year later, auditioning with the opening soliloquy from Richard III, he caught the eye of Laurence Olivier who was recruiting promising spear carriers for his new National Theatre Company. Gambon, along with Robert Stephens, Derek Jacobi and Frank Finlay, was hired as one of the "to be renowned" and played any number of small roles, appearing on cast lists as "Mike Gambon". The company initially performed at the Old Vic, their first production being Hamlet, directed by Olivier and starring Peter O'Toole. Gambon played for four years in many NT productions, including named roles in The Recruiting Officer and The Royal Hunt of the Sun, working with directors William Gaskill and John Dexter.
After three years at the Old Vic, Olivier advised Gambon to gain experience in provincial rep. In 1967, he left the NT for the Birmingham Repertory Company, which was to give him his first crack at the title roles in Othello (his favourite), Macbeth and Coriolanus. Gambon was suggested for the role of James Bond in On Her Majesty's Secret Service (1969), although he was dismissed for being even less known than George Lazenby who was cast.
His rise to fame began in 1974 when Eric Thompson cast him as the melancholy vet in Alan Ayckbourn's The Norman Conquests at Greenwich. A speedy transfer to the West End established him as a comic actor, squatting at a crowded dining table on a tiny chair and agonising over a choice between black or white coffee.
Back at the National, now on the South Bank, his next turning point was Peter Hall's premiere staging of Harold Pinter's Betrayal, a performance marked by subtlety – a production photograph shows him embracing Penelope Wilton with sensitive hands and long slim fingers (the touch of a master clock-maker).
He is also one of the few actors to have mastered the demands of the vast Olivier Theatre. As Simon Callow once said: "Gambon's iron lungs and overwhelming charisma are able to command a sort of operatic full-throatedness which triumphs over hard walls and long distances".
This was to serve him in good stead in John Dexter's masterly staging of The Life of Galileo in 1980, the first Brecht to become a popular success. Hall called him "unsentimental, dangerous and immensely powerful," and The Sunday Times called his performance "a decisive step in the direction of great tragedy... great acting," while fellow actors paid him the rare compliment of applauding him in the dressing room on the first night.
From the first Ralph Richardson dubbed him The Great Gambon, an accolade which stuck, outshining his 1990 CBE, even the later knighthood, although Gambon dismisses it as a circus slogan. But as Sheridan Morley perceptively remarked in 2000, when reviewing Nicholas Wright's Cressida: "Gambon's eccentricity on stage now begins to rival that of his great mentor Richardson". Also like Richardson, interviews are rarely given and raise more questions than they answer. Gambon is a very private person, a "non-starry star" as Ayckbourn has called him. Off-stage he prefers to stay out of the limelight. While he has won screen acclaim, his ravaged King Lear at Stratford, while he was still in his early forties, formed a double act with a red-nosed Antony Sher as the Fool sitting on his master's knee like a ventriloquist's doll.
There were also appearances in Pinter's Old Times at the Haymarket Theatre and Jonson's Volpone and the brutal sergeant in Pinter's Mountain Language. David Hare's Skylight, with Lia Williams, which opened to rave reviews at the National in 1995, transferred first to Wyndham's Theatre and then on to Broadway for a four-month run which left him in a state of advanced exhaustion. "Skylight was ten times as hard to play as anything I've ever done" he told Michael Owen in the Evening Standard. "I had a great time in New York, but wanted to return."
Gambon was not among the actors to grace Yasmina Reza's ART at Wyndham's. But together with Simon Russell Beale and Alan Bates he gave a droll radio account of the role of Marc. And for the RSC he shared Reza's two-hander The Unexpected Man with Eileen Atkins, first at The Pit in the Barbican and then at the Duchess Theatre, a production also intended for New York but finally delayed by other commitments.
In 2001 he played what he described as "'a physically repulsive" Davies in Patrick Marber's revival of Pinter's The Caretaker, but he found the rehearsal period an unhappy experience, and felt that he had let down the author. A year later, playing opposite Daniel Craig, he portrayed the father of a series of cloned sons in Caryl Churchill's A Number at the Royal Court, notable for a recumbent moment when he smoked a cigarette, the brightly lit spiral of smoke rising against a black backdrop, an effect which he dreamed up during rehearsals.
In 2004, Gambon played the lead role (Hamm) in Samuel Beckett's post-apocalyptic play Endgame at the Albery Theatre, London. In 2005 he finally achieved a lifelong ambition to play Falstaff, in Nicholas Hytner's National production of Henry IV, Parts 1 and 2, co-starring with Matthew Macfadyen as Prince Hal.
He performed as Joe in Beckett's Eh Joe, giving two performances a night at the Duke of York's Theatre in London.
In 2008 Gambon appeared in the role of Hirst in No Man's Land by Harold Pinter in the Gate Theatre, Dublin, opposite David Bradley as Spooner, in a production directed by Rupert Goold, which transferred to the London West End's Duke of York's Theatre, for which roles each received nominations for the 2009 Laurence Olivier Award for Best Actor.
In late 2009 Gambon had to withdraw from his role of W. H. Auden in The Habit of Art (being replaced by Richard Griffiths) because of ill health. In April 2010, Gambon returned once again to the Gate Theatre Dublin to appear in Samuel Beckett's Krapp's Last Tape, which transferred to London's Duchess Theatre in October 2010.
In 2012 he starred with Eileen Atkins in an adaptation of Beckett's radio play, All That Fall. Its premiere was at the Jermyn Street Theatre and it later transferred to the Arts Theatre. All That Fall had such good reviews in London that they took it to New York. In New York they recast the role of Jerry and Liam Thrift got the part. They were a huge hit in New York, in 2013, and sold out the whole run after 4 days.
In early 2015, Gambon announced that due to the increasing length of time it was taking him to memorise his lines, he was giving up stage work. He stated that 'It's a horrible thing to admit". He had previously tried using an earpiece and being given prompts by theatre staff, but found this unsatisfactory, saying that 'after about an hour I thought, "This can’t work. You can’t be in theatre, free on stage shouting and screaming and running around, with someone reading you your lines.’ "
He made his film debut in the Laurence Olivier Othello in 1965. He then played romantic leads, notably in the BBC television series, The Borderers (1968–70), in which he was swashbuckling Gavin Ker. As a result, Gambon was asked by James Bond producer Cubby Broccoli to audition for the role in 1970, to replace George Lazenby. His craggy looks soon made him into a character actor, although he won critical acclaim as Galileo in John Dexter's production of The Life of Galileo by Brecht at the National Theatre in 1980. But it was not until Dennis Potter's The Singing Detective (1986) that he became a household name. After this success, for which he won a BAFTA, his work includes such controversial films as The Cook, the Thief, His Wife & Her Lover, which also starred Helen Mirren.
In 1992 he played a psychotic general in the Barry Levinson film Toys and he also starred as Georges Simenon's detective Inspector Jules Maigret in an ITV adaptation of Simenon's series of books. He starred as Fyodor Dostoyevsky in the Hungarian director Károly Makk's movie The Gambler (1997) about the writing of Dostoyevsky's novella The Gambler. In recent years, films such as Dancing at Lughnasa (1998), Plunkett & Macleane (1998), and Sleepy Hollow (1999), as well as television appearances in series such as Wives and Daughters (1999) (for which he won another BAFTA), a made-for-TV adaptation of Samuel Beckett's Endgame (2001) and Perfect Strangers (2001) have revealed a talent for comedy. Gambon played President Lyndon B. Johnson in the television film Path to War. For this performance, he was nominated for an Emmy Award for Best Actor in a Mini-series or Movie and a Golden Globe Award for Best Actor in a Miniseries or Motion Picture Made for Television. In 2003, he appeared with Robert Duvall and Kevin Costner, playing the principal villain in the Western film Open Range.
In 2004, he appeared in five films, including Wes Anderson's quirky comedy The Life Aquatic with Steve Zissou; the British gangster flick Layer Cake; theatrical drama Being Julia; and CGI action fantasy Sky Captain and the World of Tomorrow.
In 2004, he began playing Albus Dumbledore, Hogwarts's headmaster in the third installment of J. K. Rowling's franchise, Harry Potter and the Prisoner of Azkaban, taking over the role after the death of Richard Harris. (Harris had also played Maigret on television four years before Gambon took that role.) Gambon reprised the role of Dumbledore in Harry Potter and the Goblet of Fire, which was released in November 2005 in the United Kingdom and the United States. He returned to the role again in the fifth film, 2007's Harry Potter and the Order of the Phoenix, and the sixth film, Harry Potter and the Half-Blood Prince. He appeared in the seventh film; Harry Potter and the Deathly Hallows Parts I and II, released in two parts in 2010 and 2011. Gambon told an interviewer that, when playing Dumbledore, he does not "have to play anyone really. I just stick on a beard and play me, so it's no great feat. I never ease into a role—every part I play is just a variant of my own personality. I'm not really a character actor at all...'"
In 1990 he played Jerry in Harold Pinter's Betrayal for BBC Radio 3. In 2006 he played Henry in Stephen Rea's play about Samuel Beckett's Embers for Radio 3. In 2007 he was Sam in Harold Pinter's The Homecoming for Radio 3.
Gambon has performed voiceover for the Guinness ads with the penguins. In 2007 he played major roles in Stephen Poliakoff's Joe's Palace, and the five-part adaptation of Mrs Gaskell's Cranford novels, both for BBC TV.
He also appeared as the Narrator in the British version of Kröd Mändoon and the Flaming Sword of Fire.
After Pinter's death on 24 December 2008, Gambon read Hirst's monologue selected by the playwright for Gambon to read at his funeral, held on 31 December 2008, during the cast's memorial remarks from the stage as well as at the funeral and also in Words and Music, transmitted on the BBC Radio 3 on 22 February 2009.
In 2009 he played his role as Mr. Woodhouse in a television adaptation of Jane Austen's famously irrepressible Emma, a four-hour miniseries that premiered on BBC One in October 2009, co-starring Jonny Lee Miller and Romola Garai. Gambon received a 2010 Primetime Emmy Award for Outstanding Supporting Actor in a Miniseries or a Movie nomination for his performance.
In season 1 episode 8 of BBC's Top Gear he was a Star in a Reasonably Priced Car. Around the last corner of his lap around the track he came close to rolling the car. The corner from then on was named "Gambon Corner" or simply "Gambon" in his honor.
Gambon appeared alongside Katherine Jenkins in the 2010 Christmas Special of Doctor Who, "A Christmas Carol".
In 2012 he played a role in Dustin Hoffman's directorial debut with Quartet, based on the same-titled play by Ronald Harwood and starring Maggie Smith. He had previously worked with Hoffman in the HBO horse-racing drama Luck, which was canceled in March 2012 after three horses died on set.
In 2013, Gambon provided the voice for The Prophet, a character in the MMORPG video game The Elder Scrolls Online.
In 2014, he was cast in the role of Howard Mollison on the upcoming adaptation of the best-selling book The Casual Vacancy by author J. K. Rowling, who is also the author of the Harry Potter books. The BBC One miniseries, being produced in association with HBO, will comprise three one-hour parts. Production begun 7 July 2014 in South West England.
In 2015, Gambon played Henry Tyson, a character in the Sky Atlantic TV Series Fortitude.
In early 2016, he is due to star in Mad to be Normal (previously titled Metanoia), a biopic of the Scottish psychiatrist R. D. Laing, produced by Gizmo Films.
In the New Year Honours 1998 Gambon was appointed a Knight Bachelor for "services to drama", and on Friday 17 July 1998 was invested by Prince Charles.
Gambon is a qualified private pilot and his love of cars led to his appearance on the BBC's Top Gear programme in December 2002. Gambon raced the Suzuki Liana and was driving so aggressively that it went round the last corner of his timed lap on two wheels. The final corner of the Top Gear test track has been named "Gambon" in his honour.
He appeared on the programme again on 4 June 2006, and set a time in the Chevrolet Lacetti of 1:50.3, a significant improvement on his previous time of 1:55. He clipped his namesake corner the second time, and when asked why by Jeremy Clarkson, replied, "I dunno — I just don't like it."