The 70-year-old actor, who won an Oscar for his role as real-life filmmaker James Whale in Gods And Monsters and is loved by many for starring in The Lord Of The Rings trilogy and The X-Men films, was honoured at the ceremony at London's Grosvenor House Hotel last night.
Sir Ian said: "I couldn't be more surprised or delighted. Middle-earth rejoices!"
Fellow British actor Ray Winstone received the Outstanding Contribution to British Film award, while Guy Ritchie's Sherlock Holmes picked up the Best Thriller award.
Jude Law, who plays Dr Watson in the film, was awarded the title of Empire Hero presented by Jameson Irish Whiskey, while 19-year-old British actor Aaron Johnson - who won praise for his portrayal of a young John Lennon in Nowhere Boy and more recently in action comedy Kick Ass - was named Best Newcomer, presented by Kiss 100.
James Cameron's 3D epic Avatar dominated the awards, picking up Best Film presented by Sony Make Believe, Best Director, and leading lady Zoe Saldana was named Best Actress, presented by Magic FM.
Christoph Waltz, the Inglourious Basterds star who has made a clean sweep at this year's awards season, was named Best Actor.