Thewlis had a minor role in an episode of the 1980s sitcom Up the Elephant and Round the Castle. He also appeared in an episode of popular sitcom Only Fools and Horses (1985) as a friend of Rodney. His first professional role was in the play Buddy Holly at the Regal in Greenwich.
Thewlis's breakout role was Naked (1993; dir. Mike Leigh), as the main character, Johnny, a homeless, highly intelligent, embittered, rambling street philosopher, for which Thewlis was named Best Actor by the National Society of Film Critics (United States), the London Film Critics Circle, the Evening Standard, the New York Film Critics' Circle and the Cannes Film Festival. That same year, he appeared on television as a sexual predator named James Jackson in Prime Suspect 3, opposite Helen Mirren and Ciarán Hinds. Before that, his first television appearance was in Valentine Park.
During the 1990s, Thewlis appeared in a variety of films, mostly fantasy and period, including Restoration (1995), Black Beauty (1994), Total Eclipse (1995) with Leonardo DiCaprio, The Island of Dr. Moreau (1996), Dragonheart (1996), and Seven Years in Tibet (1997), opposite Brad Pitt. He was nominated for a British Independent Film Award for Divorcing Jack (1998), and played Clov in a television film of Samuel Beckett's Endgame (2000). Notable appearances also include Bernardo Bertolucci's Besieged (1998) and Paul McGuigan's Gangster No. 1 (2000), opposite Paul Bettany and Malcolm McDowell.
He auditioned for the role of Quirinus Quirrell in the Chris Columbus directed film Harry Potter and the Philosopher's Stone, but the part went to Ian Hart. Despite missing out on the first film, he was cast in 2004 as Professor Remus Lupin in Harry Potter and the Prisoner of Azkaban. He did not have to audition as he was director Alfonso Cuarón's first choice for the role. Thewlis reprised the role in four other films in the series.
He appeared as an SS Commandant of a Nazi death camp and father of the main character in The Boy in the Striped Pyjamas, which was well received. Other credits include Ridley Scott's Kingdom of Heaven (2005), Terrence Malick's The New World (2005), and The Omen (2006).
Thewlis played the late Dr. Michael Aris, husband of Nobel Prize laureate Aung San Suu Kyi of Burma, with Malaysian actress Michelle Yeoh as Suu Kyi, in the biopic The Lady directed by Luc Besson. In 2012, he received an International Festival of Independent Cinema Off Plus Camera Award. In the same year, he also played in Separate We Come, Separate We Go, directed by Harry Potter co-star Bonnie Wright.
In June 2015, Thewlis was reported to be filming scenes for a Donald Crowhurst biopic, The Mercy, on the beach at Teignmouth, Devon, playing Donald Crowhurst's press agent, Rodney Hallworth, while Colin Firth is playing Donald Crowhurst. He also starred in Regression, a thriller released in autumn 2015. In September 2015, Thewlis starred as Inspector Goole in Helen Edmundson's BBC TV adaptation of J. B. Priestley's An Inspector Calls. In October 2015, he played King Duncan in the film Macbeth.
Year three at Hogwarts means new fun and challenges as Harry learns the delicate art of approaching a Hippogriff, transforming shape-shifting Boggarts into hilarity and even turning back time. But the term also brings danger: soul-sucking Dementors hover over the school, an ally of the accursed He-Who-Cannot-Be-Named lurks within the castle walls, and fearsome wizard Sirius Black escapes Azkaban. And Harry will confront them all.
As Lord Voldemort tightens his grip on both the Muggle and wizarding worlds, Hogwarts is no longer a safe haven. Harry suspects perils may even lie within the castle, but Dumbledore is more intent upon preparing him for the final battle fast approaching. Together they work to find the key to unlock Voldemorts defenses and to this end, Dumbledore recruits his old friend and colleague Horace Slughorn, whom he believes holds crucial information. Even as the decisive showdown looms, romance blossoms for Harry, Ron, Hermione and their classmates. Love is in the air, but danger lies ahead and Hogwarts may never be the same again.
Determined to ensure Superman's ultimate sacrifice was not in vain, Bruce Wayne aligns forces with Diana Prince with plans to recruit a team of metahumans to protect the world from an approaching threat of catastrophic proportions.
The rebellion begins! Lord Voldemort has returned, but the Ministry of Magic is doing everything it can to keep the wizarding world from knowing the truth – including appointing Ministry official Dolores Umbridge as the new Defence Against the Dark Arts professor at Hogwarts. When Umbridge refuses to teach practical defensive magic, Ron and Hermione convince Harry to secretly train a select group of students for the wizarding war that lies ahead. A terrifying showdown between good and evil awaits in this enthralling film version of the fifth novel in J.K. Rowling’s Harry Potter series. Prepare for battle!
Harry, Ron and Hermione continue their quest to vanquish the evil Voldemort once and for all. Just as things begin to look hopeless for the young wizards, Harry discovers a trio of magical objects that endow him with powers to rival Voldemort's formidable skills.
Harry, Ron and Hermione walk away from their last year at Hogwarts to find and destroy the remaining Horcruxes, putting an end to Voldemort's bid for immortality. But with Harry's beloved Dumbledore dead and Voldemort's unscrupulous Death Eaters on the loose, the world is more dangerous than ever.
Fuelled by his restored faith in humanity and inspired by Superman's selfless act, Bruce Wayne and Diana Prince assemble a team of metahumans consisting of Barry Allen, Arthur Curry and Victor Stone to face the catastrophic threat of Steppenwolf and the Parademons who are on the hunt for three Mother Boxes on Earth.
When his family moves from their home in Berlin to a strange new house in Poland, young Bruno befriends Shmuel, a boy who lives on the other side of the fence where everyone seems to be wearing striped pajamas. Unaware of Shmuel's fate as a Jewish prisoner or the role his own Nazi father plays in his imprisonment, Bruno embarks on a dangerous journey inside the camp's walls.
Suave, charming and volatile, Reggie Kray and his unstable twin brother Ronnie start to leave their mark on the London underworld in the 1960s. Using violence to get what they want, the siblings orchestrate robberies and murders while running nightclubs and protection rackets. With police Detective Leonard "Nipper" Read hot on their heels, the brothers continue their rapid rise to power and achieve tabloid notoriety.
Every town on Discworld knows the stories about rats and pipers, and Maurice - a street wise tomcat - leads a band of educated ratty friends (and a stupid kid) on a nice little earner. Piper plus rats equals lots and lots of money. Until they run across someones playing a different tune. Now Maurice and his rats must learn a new concept: evil...
The Theory of Everything is the extraordinary story of one of the world’s greatest living minds, the renowned astrophysicist Stephen Hawking, who falls deeply in love with fellow Cambridge student Jane Wilde.
Jeffrey 'The Dude' Lebowski, a Los Angeles slacker who only wants to bowl and drink White Russians, is mistaken for another Jeffrey Lebowski, a wheelchair-bound millionaire, and finds himself dragged into a strange series of events involving nihilists, adult film producers, ferrets, errant toes, and large sums of money.
Novelist Catherine Tramell is once again in trouble with the law, and Scotland Yard appoints psychiatrist Dr. Michael Glass to evaluate her. Though, like Detective Nick Curran before him, Glass is entranced by Tramell and lured into a seductive game.