The Revenant swept the board with five awards at the Baftas including best film, best director and best actor.
Leonardo DiCaprio was crowned best actor for his lead role in the film after a closely-fought battle with the British actor Eddie Redmayne. His win will prompt speculation that he could finally be in line for an Oscar this year.
Brie Larson picked up the best actress gong for her role in Room at the star-studded awards.
British winners included Kate Winslet for best supporting actress, Mark Rylance as best supporting actor, and the Star Wars actor John Boyega, who was named as the rising star of the night.
The clear winner of the night, though, was The Revenant - which landed best film, best leading actor for DiCaprio and best director for Alejandro Innaritu.
Inarritu said it was "overwhelming" as he picked up the award for best film. He called his best director win "a true honour" and paid tribute to the film's cast, led by DiCaprio.
Redmayne had earlier tipped DiCaprio to beat him on the night, in a playful rivalry between the two stars that provided much of the drama of the night.
Brie Larson's award was picked up on her behalf by the Room director Lenny Abrahamson, who described her as "one of the best actors of her generation".
"Brie, looking for a little bit of something light and nice to do after Room, is wrestling a large gorilla in Australia," he joked.
Kate Winslet won the best supporting actress award for her performance in Steve Jobs, the biopic on Apple's co-founder.
Collecting her third Bafta, Winslet, 40, hailed director Danny Boyle as "amazing" to work with and called the film's lead star Fassbender "an extraordinary actor".
She also mentioned her husband Ned Rocknroll, saying: "Hi babe, happy Valentine's day."
Fellow British star Mark Rylance was named best supporting actor for his role as a Russian spy in Bridge Of Spies.
The film's director Steven Spielberg collected the award on his behalf as Rylance is performing in the off-Broadway play Nice Fish.
Presenting the award, Australian actress Rebel Wilson had a dig at the Oscars diversity row.
She said: "Idris Elba you're making me nervous... I'm sociologically programmed to want chocolate on Valentine's Day."
The night also saw David Bowie and Alan Rickman remembered during a memorial section.