Fans lined up alongside the red carpet to get a glimpse of celebrities including Amy Adams, Eddie Redmayne and Martin Scorsese.
The event, at London's Royal Opera House in Covent Garden, is hosted by Stephen Fry with big name guests including Chiwetel Ejiofor and Gillian Anderson.
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The star of The Fall and The X-Files posed for photographers in a vintage 1949 dress, while Luther star Ruth Wilson was dressed more for the chilly evening weather in a silver suit.
Another of the stars of hit film 12 Years A Slave, Lupita Nyong'o, posed for pictures on the red carpet in an emerald green Dior dress with matching shoes.
The event, formally known as the EE British Academy Film Awards, is broadcast on BBC1.
Also among the guests is the Duke of Cambridge, who is presenting the Fellowship award to Dame Helen Mirren.
William, who is president of the academy, said the awards were "a wonderful way" to recognise the UK film industry.
Writing in the official programme for the event, he said: "Excellence permeates every award category, from compelling leading performances to ingenious production design."