Jim Broadbent was named best supporting actor
Jim Broadbent was the only UK actor to pick up an award, named best supporting actor for his role in Iris.
Rock star Sting was given the prize for best original song for Until..., used in the film Kate and Leopold.
And Scottish musician Craig Armstrong, who created the wild music that accompanied Moulin Rouge, won the award for best original score.
UK stars including Ewan McGregor, Judi Dench, Helen Mirren and Kate Winslet had all been in the running for acting awards, but Broadbent was the only British winner.
In Iris, he plays John Bayley, the husband of late British novelist and philosopher Iris Murdoch who cares for her while she is in the grip of Alzheimer's disease.
"This is amazing, I couldn't be more surprised, and I really haven't got anything worked out," he said by way of an acceptance speech.
"I'd just like to thank the producers, the director, the writers, the other actors, particularly Judi Dench, who I had so many scenes with and worked... and she made it so easy.
"And Kate Winslet, who made the film so wonderful, even though I didn't really act with her."
Before the ceremony, he had joked that he was on the verge of passing out because so many of his heroes were there.
But he is now an established star himself after his role in Iris as well as acclaimed supporting parts in Moulin Rouge and Bridget Jones's Diary.
Broadbent, 52, beat compatriots Jude Law, for AI, and Ben Kingsley, for Sexy Beast, as well as Steve Buscemi, Hayden Christensen and Jon Voight in the best supporting actor category.
Dench and Winslet were both nominated for their roles in Iris, while Tilda Swinton was also up for the best dramatic actress gong for her role in The Deep End.
Ewan McGregor lost out in the best actor in a musical or comedy for his role in Moulin Rouge.
Helen Mirren and Dame Maggie Smith were both nominated for their supporting roles in period drama Gosford Park, which has a largely UK cast, and for which US film-maker Robert Altman won best director.
Sting can add the Golden Globe to the lifetime achievement award he will pick up at the Brits next month.
He said working on the music for comedy Kate and Leopold, which stars Meg Ryan and Hugh Jackman, helped him start work again after 11 September.
"This movie just kind of took me out of that depression," he said.
"I'm going to give it my daughter," he said of the award. "She was the first person I played the song for."
The other UK victor, Craig Armstrong, is now one of the world's most respected soundtrack composers, adding this award to a Bafta for his work on the Romeo and Juliet soundtrack.
He has collaborated with artists including Massive Attack, Madonna, U2 and Tina Turner in the past, and wrote Texas's hit single I Don't Want A Lover.
He has also created soundtracks for Kiss of the Dragon, The Bone Collector, Best Laid Plans and Plunkett & Macleane, as well as releasing his own contemporary classical and modern electronic works.