Blanchett was a vision in white, while Delevigne chose a black fitted gown for the star-studded event to celebrate the work of The Royal Marsden Hospital, which was sponsored by fashion designer Ralph Lauren.
Hollywood star Blanchett was typically ethereal in a one-shouldered, Grecian-style gown which she paired with chandelier earrings and a mini clutch.
Model-of-the-minute Delevingne meanwhile went for a fitted, halterneck dress with an embellished bodice. Dramatic smokey eyemakeup and a sleek upstyle insured this was a head-turning look for her.
Kate Moss vamped it up in a black full-length dress with a sheer sleeve and thigh-high split. A pair of strappy sandals, boxy clutch aand gorgeous earrings and a bracelet completed the outfit.
Moss looked happy as she posed alongside her rocker husband Jamie Hince, who scrubbed up nicely in a black suit and tie.
Emma Watson demonstrated that she's not afraid to take a style risk in an unusual dress, which featured a white shirt and flowing grey skirt. The very ladylike dress was set off with a loose upstyle and burgundy lipstick.
The Wolf of Wall Street's Margot Robbie went for a daring backless grey satin and jersey gown.
Helena Bonham Carter chose a navy strapless ruffled gown with a fulll skirt, wearing her hair in a curled upstyle.
Sherlock star Benedict Cumberbatch was as dapper as ever in a classic black suit.
Kate Moss and Cara Delevingne posed together at the event
