Hopkins was born on New Year's Eve 1937, in Margam, a suburb of Port Talbot, Glamorgan. His parents were Annie Muriel (née Yeates) and Richard Arthur Hopkins, a baker. He stated his father’s working class values have always underscored his life. “Whenever I get a feeling that I may be special or different, I think of my father and I remember his hands – his hardened, broken hands". His school days were unproductive; he would rather immerse himself in art, such as painting and drawing, or playing the piano, than attend to his studies. In 1949, to instill discipline, his parents insisted he attend Jones' West Monmouth Boys' School in Pontypool. He remained there for five terms and was then educated at Cowbridge Grammar School in the Vale of Glamorgan. In a 2002 interview he stated: "I was a poor learner, which left me open to ridicule and gave me an inferiority complex. I grew up absolutely convinced I was stupid." In desperation, his parents sent him off to boarding school, where the headmaster told him he was "hopeless" and he developed a "sheer contempt for authority." He stumbled into acting at 17 with a YMCA group (his one line: "Blessed are the meek, for they shall inherit the earth").

Hopkins has been a patron of the YMCA centre in his home town of Port Talbot, South Wales for more than 20 years, having first joined the YMCA in the 1950s. He supports other various philanthropic groups. He was a Guest of Honour at a Gala Fundraiser for Women in Recovery, Inc., a Venice, California-based non-profit organisation offering rehabilitation assistance to women in recovery from substance abuse. He is also a volunteer Teacher at the Ruskin School of Acting in Santa Monica, California. Hopkins served as the Honorary Patron of The New Heritage Theatre Company in Boise, Idaho from 1997-2007, participating in fundraising and marketing efforts for the repertory theatre.

Hopkins was influenced and encouraged by Welsh compatriot Richard Burton, whom he met at the age of 15. Hopkins promptly enrolled at the Royal Welsh College of Music & Drama in Cardiff, from which he graduated in 1957. After two years in the British Army doing his national Service, he moved to London where he studied at the Royal Academy of Dramatic Art.

Hopkins made his first professional stage appearance in the Palace Theatre, Swansea, in 1960 with Swansea Little Theatre's production of Have a Cigarette. In 1965, after several years in repertory, he was spotted by Laurence Olivier, who invited him to join the Royal National Theatre in London. Hopkins became Olivier's understudy, and filled in when Olivier was struck with appendicitis during a 1967 production of August Strindberg's The Dance of Death. Olivier later noted in his memoir, Confessions of an Actor, that

Hopkins has been married three times: to Petronella Barker from 1966 to 1972; to Jennifer Lynton from 1973 to 2002; and, since 2003, to Stella Arroyave. On Christmas Eve 2012, he celebrated his 10th wedding anniversary by having a blessing at a private Service at St David's Cathedral, Pembrokeshire in the most westerly point of Wales. He has a daughter, Actress and singer Abigail Hopkins (born 20 August 1968), from his first marriage.

Hopkins is a recovering alcoholic; he has stayed sober since he stopped drinking just after Christmas 1975. In 2002, he told the New York Times that he woke up in a Phoenix hotel room with no memory of having driven from Los Angeles. "It was two days before his 38th birthday. Still, he continued to spiral downward, at times sitting at home for hours without saying a word. He'd climb in his car and cruise aimlessly for days: once he went on a drive and didn't return for two months. "If there is someone fighting within you, it makes your life unbearable," he said. "Anger has to be converted into something else or it destroys you." He said that a major help in his recovery was his belief in God. He has criticised atheism, saying in 2011 that "being an atheist must be like living in a closed cell with no windows". In an interview with Larry King in 2016, Hopkins described himself as an agnostic and said he believed in a "superior consciousness in all of us". He gave up smoking using the Allen Carr method. In 2008, he embarked on a weight loss program, and by 2010, he had lost 80 pounds.

In 1980, he starred in The Elephant Man as the English Doctor Sir Frederick Treves, who attends to Joseph Merrick (portrayed by John Hurt), a severely deformed man in 19th century London. That year he also starred opposite Shirley MacLaine in A Change of Seasons and famously said "she was the most obnoxious Actress I have ever worked with." In 1983, Hopkins also became a company member of The Mirror Theater Ltd's Repertory Company. He remained an enthusiastic member of the company and the Mirror’s Producing Artistic Director Sabra Jones visited him in London in 1986 to discuss moving Pravda to New York from the National Theatre. In 1984, he starred opposite Mel Gibson in The Bounty as william Bligh, captain of the Royal Navy ship the HMS Bounty, in a retelling of the mutiny on the Bounty. In 1992, Hopkins portrayed Professor Van Helsing in Francis Ford Coppola's Bram Stoker's Dracula.

Anthony Hopkins was made a Commander of the Order of the British Empire (CBE) in 1987, and was knighted as a Knight Bachelor at Buckingham Palace in 1993 for services to the arts. In 1988, Hopkins was made an Honorary D.Litt and in 1992 was awarded Honorary fellowship from the University of Wales, Lampeter. He was made a freeman of his home town, Port Talbot, in 1996.

In 1990, Hopkins directed a film about his Welsh compatriot, poet Dylan Thomas, titled Dylan Thomas: Return Journey, which was his directing debut for the screen. In the same year, as part of the restoration process for the Stanley Kubrick film Spartacus, Hopkins was approached to re-record lines from a scene that was being added back to the film; this scene featured Laurence Olivier and Tony Curtis, with Hopkins recommended by Olivier's widow, Joan Plowright to perform her late husband's part thanks to his talent for mimicry.

Hopkins is a gifted mimic, adept at turning his native Welsh accent into whatever is required by a character. He duplicated the voice of his late mentor, Laurence Olivier, for additional scenes in Spartacus in its 1991 restoration. His interview on the 1998 relaunch edition of the British TV talk show Parkinson featured an impersonation of Comedian Tommy Cooper. Hopkins has said acting "like a submarine" has helped him to deliver credible performances in his thrillers. He said, "It's very difficult for an actor to avoid, you want to show a bit. But I think the less one shows the better."

Richard Attenborough, who directed Hopkins on five occasions, found himself going to great lengths during the filming of Shadowlands (1993) to accommodate the differing approaches of his two stars (Hopkins and Debra Winger), who shared many scenes. Whereas Hopkins, preferring the spontaneity of a fresh take, liked to keep rehearsals to a minimum, Winger rehearsed continuously. To allow for this, Attenborough stood in for Hopkins during Winger's rehearsals, only bringing him in for the last one before a take. The Director praised Hopkins for "this extraordinary ability to make you believe when you hear him that it is the very first time he has ever said that line. It's an incredible gift."

In 1996, he directed August, an adaptation of Chekhov's Uncle Vanya set in Wales. His first screenplay, an experimental drama called Slipstream, which he also directed and scored, premiered at the Sundance Film Festival in 2007. In 1997, Hopkins narrated the BBC natural documentary series, Killing for a Living, which showed predatory behaviour in nature. He narrated episode 1 through 3 before being replaced by John Shrapnel.

Hopkins has offered his support to various charities and appeals, notably becoming President of the National Trust's Snowdonia Appeal, raising funds for the preservation of Snowdonia National Park in north Wales. In 1998 he donated £1 million towards the £3 million needed to aid the Trust's efforts in purchasing parts of Snowdon. Prior to the campaign, Hopkins authored Anthony Hopkins' Snowdonia, which was published in 1995. Due to his contributions to Snowdonia, in addition to his film career, in 2004 Hopkins was named among the 100 Welsh Heroes in a Welsh poll.

Hopkins contributed toward the refurbishment of a £2.3 million wing at his alma mater, the Royal Welsh College of Music & Drama in Cardiff, named the Anthony Hopkins Centre. It opened in 1999.

Hopkins resides in Malibu, California. He had moved to the US once before during the late 1970s to pursue his film career, but returned to London in the late 1980s. However, he decided to return to the US following his 1990s success. Retaining his British citizenship, he became a naturalised US citizen on 12 April 2000, with Hopkins stating: "I have dual citizenship; it just so happens I live in America".

Hopkins is an admirer of the Welsh Comedian Tommy Cooper. On 23 February 2008, as patron of the Tommy Cooper Society, he unveiled a commemorative statue in the entertainer's home town of Caerphilly. For the ceremony, he donned Cooper's trademark fez and performed a comic routine.

On 24 February 2010, it was announced that Hopkins had been cast in The Rite, which was released on 28 January 2011. He played a priest who is "an expert in exorcisms and whose methods are not necessarily traditional". Hopkins, who is quoted as saying "I don't know what I believe, myself personally", reportedly wrote a line--"Some days I don't know if I believe in God or Santa Claus or Tinkerbell"—into his character in order to identify with it. On the other hand, in other sources from the same time, he is quoted as saying that he did believe in God and had done so for decades. On 21 September 2011, Peter R. de Vries named Hopkins in the role of the Heineken owner Freddy Heineken in a Future film about his kidnapping.

On 31 October 2011, André Rieu released an album including a waltz which Hopkins had composed in 1964, at the age of 26. Hopkins had never heard his composition, "And the Waltz Goes On", before it was premiered by Rieu's orchestra in Vienna; Rieu's album was given the same name as Hopkins' piece.

In January 2012, Hopkins released an album of classical music, entitled Composer, performed by the City of Birmingham Symphony Orchestra, and released on CD via the UK radio station Classic FM. The album consists of nine of his original works and film scores, with one of the pieces titled "Margam" in tribute to his home town near Port Talbot in Wales.

Hopkins was nervous prior to going on stage, but since that night he has relaxed, quoting his mentor: "He [Olivier] said: 'Remember: nerves is [sic] Vanity – you’re wondering what people think of you; to hell with them, just jump off the edge’. It was great advice.” Despite his success at the National, Hopkins tired of repeating the same roles nightly and yearned to be in films. He made his small-screen debut in a 1967 BBC broadcast of A Flea in Her Ear. His first starring role in a film came in 1964 in Changes, a short directed by Drewe Henley, written and produced by James Scott and co-starring Jacqueline Pearce. In 1968, he got his break in The Lion in Winter playing King Richard the Lionheart. Although Hopkins continued in theatre (most notably at the National Theatre as Lambert Le Roux in Pravda by David Hare and Howard Brenton and as Antony in Antony and Cleopatra opposite Judi Dench as well as in the Broadway production of Peter Shaffer's Equus) he gradually moved away from it to become more established as a television and film actor. He portrayed Charles Dickens in the BBC television film The Great Inimitable Mr. Dickens in 1970, and Pierre Bezukhov in the BBC's mini series War and Peace (1972). Making a name for himself as a screen actor, in 1972 he starred as British Politician David Lloyd George in Young Winston, and in 1977 he played British Army officer John Frost in the World War II-set film A Bridge Too Far. Both of these films were directed by Richard Attenborough, who described Hopkins as “unquestionably the greatest actor of his generation”.

In October 2015, Hopkins appeared as Sir in a BBC Two production of Ronald Harwood's The Dresser, alongside Ian McKellen, Edward Fox and Emily Watson. The Dresser is set in a London theatre during the Blitz, where an aging actor-manager, Sir, prepares for his starring role in King Lear with the help of his devoted dresser, Norman. Hopkins described his role as Sir as “the highlight of my life”. “It was a chance to work with the actors I had run away from. To play another actor is fun because you know the ins and outs of their thinking – especially with someone like Sir, who is a diabolically insecure, egotistical man."

Bringing his quiet, enigmatic style to his horror roles, in a 2016 interview with the Radio Times, Hopkins spoke of his ability to frighten people since he was a boy growing up in Port Talbot, Wales. "I don't know why but I've always known what scares people. When I was a kid I’d tell the girls around the street the story about Dracula and I’d go 'th-th-th' (the sucking noise which he reproduced in The Silence of the Lambs). As a result, they’d run away screaming." He recalled going through the film's script for the first time with fellow cast members. "I didn't know what they were going to make of it but I'd prepared it – my first line to Jodie Foster was: 'Good morning. You’re one of Jack Crawford’s aren't you'?. Everyone froze. There was a silence. Then one of the producers said, 'Holy crap, don't change a thing'." Director Jonathan Demme described Hopkins as "A good man trapped inside an insane mind".

In January 2017, in an interview with The Desert Sun, Hopkins reported that he had been diagnosed with Asperger syndrome, but that he was "high end".