He spent the last 12 years of his life living in Room 758 at the world-famous Savoy Hotel in London. His room was located in the "Courtside" section of the hotel. It did have a view of the river, but not as fine a view as the "Hotel" section riverside rooms. He only had his room cleaned once a week and very rarely notified the hotel that he was out of his room, so they had to check his door ten times a day to see if his "Do Not Disturb" sign flipped around to say "Make Up My Room".
He was a guest professor at the University of Scranton in the mid-1980s, teaching Theatre Arts courses.
He was awarded the 1990 London Evening Standard Theatre Award for Best Actor for his performance in Henry IV.
He won the role of King Arthur in Camelot (1967), the film version of Alan Jay Lerner & Frederick Loewe's hit musical, after close friend and drinking buddy Richard Burton, who had played Arthur in the original 1960 Broadway production, turned down an offer to reprise the role in the film. Burton had had a huge success with Lerner & Lowe's show, winning a 1961 Tony Award for Best Actor in a Musical. Harris later replaced Burton in the roadshow of the 1980 revival of the musical when Burton was unable to continue due to bursitis, a tour that ended up back on Broadway, with Harris as Arthur, in 1981.
His brother Dermot was married to actress Cassandra Harris and had two children. After his death she married Pierce Brosnan and they became Brosnan's stepchildren.
In 1979 he was diagnosed with hyperglycemia, a condition in which an excessive amount of glucose circulates in the blood plasma.
In an interview on "The Tonight Show Starring Johnny Carson" (1962), Harris told a story about when he was a young actor playing Seyton in a theatrical production of "Macbeth." The lead actor was a real jerk to him, making constant demeaning references to Harris's Irish heritage. On opening night, Harris couldn't take it anymore. In Act V, Macbeth turns to him and says, "Wherefore was that cry?" Harris was supposed to reply, "The queen, my lord, is dead," after which Macbeth goes into his famous soliloquy about "Tomorrow, and tomorrow, and tomorrow." However, Harris decided instead to say, "Oh, don't worry. She's fine. She'll be up and about in ten minutes." He ruined the performance and was promptly fired.
In his youth he was a fan of Marlon Brando, and could imitate or parody his performance in On the Waterfront (1954) at the drop of a hat. However he did not get along with Brando while filming Mutiny on the Bounty (1962) and blamed the American star's on-set behavior for the film going over budget and over schedule. During the 1960s he often criticized Brando's eccentric movie choices in interviews.
Is one of only two actors to appear in two Best Picture winners from the 1990s. He appeared in 1992's Best Picture, Unforgiven (1992), and 2000's Best Picture, Gladiator (2000). The only other actor to do this was Ralph Fiennes, who appeared in Schindler's List (1993) and The English Patient (1996). Fiennes later followed Harris into the Harry Potter films.
It was his lifelong ambition to play Hamlet. He never did, although he referred to This Sporting Life (1963) as his Hamlet and The Field (1990) as his Lear. He later had one final attempt at an updated version of Lear with My Kingdom (2001).
Joined the Knights of Malta (SMOM), despite his two divorces.
Member of the Royal Shakespeare Company (RSC) in Stratford Upon Avon, England, since the early 1960s. His last appearance on the Swan stage (RSC main) was in the mid-1990s.
Once said in an interview that he had a great fascination with authority figures and their use of power. During his career he portrayed King Arthur in Camelot (1967); Oliver Cromwell in Cromwell (1970); King Richard the Lionheart in Robin and Marian (1976); Roman Emperor Marcus Aurelius in Gladiator (2000) and Headmaster Albus Dumbledore in the first two Harry Potter films, Harry Potter and the Sorcerer's Stone (2001) and Harry Potter and the Chamber of Secrets (2002).
One of 9 children born to Limerick farmer Ivan Harris and his wife, the former Mildred Harty.
Only agreed to take the part of Albus Dumbledor in Harry Potter and the Sorcerer's Stone (2001) after his then 11-year-old granddaughter threatened never to speak to him again if he didn't.
Producers were initially reluctant to cast Harris as King Arthur in Camelot (1967) due to his limited singing ability. Harris was cast after Richard Burton, who had played the part on Broadway in 1961, demanded too much money. The Irish actor insisted on doing his own singing live and later enjoyed a successful pop career, touring America in 1972.
Received an Honorary Doctorate from the University of Scranton in 1987.
Received the Laurence Olivier Award for his acclaimed performances at the Royal National Theatre, London, England.
Turned down the role of Commodus in The Fall of the Roman Empire (1964), then went on to play Commodus' father Marcus Aurelius (who dies at his son's hands) in Gladiator (2000).
Uncle of actress Annabelle Wallis.