Garfield was honoured for his roles in 'The Social Network' and 'Never Let Me Go', reports the BBC.
Accepting his award in a filmed message, he said: "I really, really appreciate it and intend to let this spur me and provide more fuel for my fire."
Kristin Scott Thomas was named best actress for her role in French film Leaving, while Peter Mullan's Glasgow-set drama Neds won best film.
Actor Stephen Mangan hosted this year's awards, held at the London Film Museum.
Garfield is playing Spider-Man in a new film that focuses on the formative years of the comic book superhero, set for release in 2012. (ANI)