In a mysterious video released today, we can see only a slender body dressed in a beaded gown, a darkly romantic piece from their Christmas 2012 collection and the hashtag #whosthatgirl.
The video is the first of a series of cryptic clues which will be released every day from now until Tuesday, when the glamorous campaign star will be unveiled.
Until then, its up to you to guess who it could be, using the #whosthatgirl hashtag on Twitter and Facebook. Those who guess correctly before the big reveal will be in with a chance of winning £500 worth of Topshop vouchers.
Can you guess who it is? View the video below and tweet @Topshop using #whosthatgirl if you think you know...