The film's stars, Frances McDormand and Sam Rockwell, won best actress and best supporting actor, respectively, while McDonagh took home best original screenplay.
McDonagh lost out in the best director category to "The Shape of Water's" Guillermo Del Toro. "The Shape of Water" took the second biggest haul of the night with three awards, while "Blade Runner 2049" and "Darkest Hour" took two apiece.
The "Time's Up" campaign against sexual misconduct was a recurring theme throughout the evening. Many of the female attendees wore black outfits in a gesture of protest.
In his acceptance speech, McDonagh expressed the hope that such protests would bring about change.
"Our film is a hopeful one in lots of ways but it's also an angry one, and as we've seen this year, sometimes anger is the only way to get people to listen and to change, so we're thrilled that BAFTA has recognised this," he said.
In addition, many in attendance wore badges citing the campaign against sexual harassment, while honourees and presenters, including Sam Rockwell and British actress Lily James expressed support for the movement.
The night's biggest female winner, McDormand, did not join in the sartorial protest, saying in her acceptance speech that though she supported the movement, she had "a little trouble with compliance but I want you to know I stand in alliance with my sisters in black," said McDormand.
"In drama school I was told I wasn't naturally gifted and I should work at it. So I did," joked the actress. It was McDormand's first BAFTA award after four nominations.
"Three Billboards Outside Ebbing, Missouri" took the first award of the night for outstanding British film. Sam Rockwell made it two as he won best supporting actor, beating out co-star Woody Harrelson. "I stand on the shoulders of strong, intelligent, riotous women," said Rockwell, telling McDormand she was an inspiration, before dedicating the award to "my pal Alan Rickman."
Claiming best original screenplay for the film, McDonagh called Rockwell his muse. "Three Billboards" marked the pair's third collaboration following a stage play and the film "Seven Psychopaths." The win was McDonagh's second BAFTA win in the original screenplay category; he previously won for 2008's "In Bruges."
Gary Oldman won best actor for his role as Winston Churchill in Joe Wright's "Darkest Hour," and thanked Churchill, who he said had "held the line for integrity, honor and freedom for his country and the world." "Darkest Hour" also won for its makeup and hair.
Accepting his director award, Guillermo Del Toro paid tribute to the legacy of Michael Powell and Emeric Pressburger, Charlie Chaplin, Stan Laurel and novelist Mary Shelley among his British influences. "She gave voice to the voiceless," said the director of Shelley. It was the Mexican filmmaker's second BAFTA, after having won best foreign language film for his 2006 Spanish-language film "Pan's Labyrinth."
Allison Janney won supporting actress for her role in "I, Tonya." The actress joked she had to clear up a lie she had been perpetrating for years: that she hadn't actually graduated from the U.K.'s world renowned Royal Academy of Dramatic Arts, but that she had done a two-week course there.
With "Black Panther" dominating in cinemas around the world, one of its stars, British actor Daniel Kaluuya, had double cause to celebrate Sunday night as he was awarded the EE Rising Star BAFTA award, the only award voted for by the public. Having worked steadily in British film and television over the past decade, Kaluuya saw his breakout role in Jordan Peele's "Get Out" bring him to global public attention as well as net him BAFTA and Oscar nominations as best actor. Kaluuya, who recently finished shooting Steve McQueen's "Widows," beat out Florence Pugh, Josh O'Connor, Tessa Thompson and Timothee Chalamet for the award.
"I am a product of arts funding in the U.K.," said Kaluuya, thanking those who funded and supported arts funding in the country.
Pixar's "Coco" claimed best animated film. It marked the seventh time Pixar has won the BAFTA award since its animated prize's inception in 2006. Director Lee Unkrich previously won for Pixar's 2010 film "Toy Story 3." "Representation matters. Marginalized people deserve to feel like they belong," said Unkrich, on the importance of having non-white characters on screen. "I hope we've made a difference and I hope it's just the beginning."
Raoul Peck's "I Am Not Your Negro," about U.S. novelist and social critic James Baldwin, claimed the BAFTA for best documentary. Peck said Baldwin was "the perfect image of a great humanist."
Park Chan-wook's Korean language film "The Handmaiden" claimed the BAFTA for film not in the English language.
James Ivory collected the best adapted screenplay BAFTA for "Call Me by Your Name." It was the 89 year old's third BAFTA but his first for screenplay. He previously won twice for producing best film winners "A Room with a View" and "Howards End."
The team behind the special visual effects of "Blade Runner 2049" beat out heavyweight competition from "Dunkirk," "The Shape of Water," "Star Wars: The Last Jedi" and "War for the Planet of the Apes."
"I Am Not a Witch" won outstanding debut by a British writer, director or producer. Writer-director Rungano Nyoni said: "I want to thank all the people who said yes to me, without your support we couldn't have made this, and all those who said no, frankly, because you really spurred me on."
Celia Imrie presented the previously announced special BAFTA award for Outstanding British Contribution to Cinema to the U.K.'s National Film and Television School (NFTS). Imrie cited just of a few of the NFTS' graduates including Oscar-winning animator Nick Park and acclaimed cinematographer Roger Deakins. Accepting the award Jon Wardle, director of the school, said the NFTS' job was to find "the new Roger Deakins, wherever they come, and make sure they have the support they need."
Just moments later the NFTS scored its fifth consecutive win in the British short animation category, with stop-motion film "Poles Apart," while Deakins went on to win the BAFTA for cinematography for Denis Villeneuve's "Blade Runner 2049." It marked Deakins' fourth BAFTA win from nine nominations. His previous wins in the category came for the Coen brothers' films "The Man Who Wasn't There," "No Country for Old Men" and "True Grit."
As previously announced, Ridley Scott was honored with a BAFTA Fellowship, the body's highest accolade, for his outstanding and exceptional contribution to the industry. The veteran British director and producer received a standing ovation as he took to the stage. "It's been 40 years in this business and this is the first time they've given me anything," said Scott. "I'm constantly reminded by journalists that I'm an octogenarian. I wonder if the real reason behind the award is 'better give him something before it's too late'."
Greta Gerwig's "Lady Bird," Paul King's "Paddington 2" and Paul McGuigan's "Film Stars Don't Die in Liverpool" all went home empty-handed despite three nominations each.
Full list of 2018 BAFTAs winners:
BEST FILM "Three Billboards Outside Ebbing, Missouri," Graham Broadbent, Pete Czernin, Martin McDonagh
DIRECTOR "The Shape of Water," Guillermo Del Toro
LEADING ACTOR Gary Oldman, "Darkest Hour"
LEADING ACTRESS Frances McDormand, "Three Billboards Outside Ebbing, Missouri"
SUPPORTING ACTOR Sam Rockwell, "Three Billboards Outside Ebbing, Missouri"
SUPPORTING ACTRESS Allison Janney, "I, Tonya"
OUTSTANDING BRITISH FILM "Three Billboards Outside Ebbing, Missouri," Martin McDonagh, Graham Broadbent, Pete Czernin
ANIMATED FILM "Coco," Lee Unkrich, Darla K. Anderson
FILM NOT IN THE ENGLISH LANGUAGE "The Handmaiden," Park Chan-wook, Syd Lim
DOCUMENTARY "I Am Not Your Negro," Raoul Peck
EE RISING STAR AWARD (VOTED FOR BY THE PUBLIC) Daniel Kaluuya
OUTSTANDING DEBUT BY A BRITISH WRITER, DIRECTOR OR PRODUCER "I Am Not a Witch," Rungano Nyoni (Writer/Director), Emily Morgan (Producer)
ORIGINAL SCREENPLAY "Three Billboards Outside Ebbing, Missouri," Martin McDonagh
ADAPTED SCREENPLAY "Call Me by Your Name," James Ivory
ORIGINAL MUSIC "The Shape of Water," Alexandre Desplat
CINEMATOGRAPHY "Blade Runner 2049," Roger Deakins
EDITING "Baby Driver," Jonathan Amos, Paul Machliss
COSTUME DESIGN "Phantom Thread," Mark Bridges
PRODUCTION DESIGN "The Shape of Water," Paul Austerberry, Jeff Melvin, Shane Vieau
MAKE UP & HAIR "Darkest Hour," David Malinowski, Ivana Primorac, Lucy Sibbick, Kazuhiro Tsuji
SPECIAL VISUAL EFFECTS "Blade Runner 2049," Richard R. Hoover, Paul Lambert, Gerd Nefzer, John Nelson
SOUND "Dunkirk," Alex Gibson, Richard King, Gregg Landaker, Gary A. Rizzo, Mark Weingarten
BRITISH SHORT ANIMATION "Poles Apart," Paloma Baeza, Ser En Low
BRITISH SHORT FILM "Cowboy Dave," Colin O'Toole, Jonas Mortense
OUTSTANDING BRITISH CONTRIBUTION TO CINEMA (PREVIOUSLY ANNOUNCED) National Film and Television School (NFTS)
BAFTA FELLOWSHIP (PREVIOUSLY ANNOUNCED) Ridley Scott
Over the course of a year, film follows Vancouver Pride Society president Ken Coolen to various international Pride events, including Poland, Hungary, Russia, Sri Lanka and others where there is great opposition to pride parades. In North America, Pride is complicated by commercialization and a sense that the festivals are turning away from their political roots toward tourism, party promotion and entertainment. Christie documents the ways larger, more mainstream Pride events have supported the global Pride movement and how human rights components are being added to more established events. In the New York sequence, leaders organize an alternative Pride parade, the Drag March, set up to protest the corporatization of New York Pride. A parade in São Paulo, the world's largest Pride festival, itself includes a completely empty float, meant to symbolize all those lost to HIV and to anti-gay violence.