Sophie looked elegant as she supported her husband-to-be, choosing a long black dress with sheer sleeves and floral appliques around the bodice and skirt. Benedict proudly stood with his arm wrapped around the beautiful brunette as they posed for pictures together at the screening.
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Benedict Cumberbatch and Sophie Hunter have made their red carpet debut
Their sweet appearance comes two weeks after Benedict and Sophie announced their plans to marry in The Times newspaper in a notice that read, "Mr BT. Cumberbatch and Miss S.I. Hunter: The engagement is announced between Benedict, son of Wanda and Timothy Cumberbatch of London, and Sophie, daughter of Katharine Hunter of Edinburgh and Charles Hunter of London."
The Sherlock star told USA Today the announcement was "what I would have done if I wasn't famous".
"It's a normal thing to do in my country," he said. "It was a way of telling our friends who we hadn't been able to tell before (they saw) some grainy shot of a ring on her finger."
The future Mr and Mrs Cumberbatch announced their engagement earlier this month
Benedict and Sophie have gone to great lengths to avoid being publicly seen together since they started dating earlier this year. The couple, who first met in 2009 when they appeared in the film Burlesque Fairytales, were first spotted together in June when they attended the French Open.
Meanwhile, Benedict is already generating Oscar buzz for his performance in The Imitation Game as mathematician Alan Turing, whose brilliant mind helped crack the German Enigma Code during World War II.
Benedict Cumberbatch is receiving rave reviews for his portrayal of Alan Turing
Benedict is receiving rave reviews for his sensitive portrayal alongside Keira Knightley in the film, which is hotly tipped to be a strong contender at next year's Academy Awards.
Speaking at the LA premiere of the film, the star told E! News that is grateful for the support he has received in his career and said he felt lucky to have such a loyal following, but added, "The only support I really need to be honest is the woman I love, who I proposed to".