After lending her expertise at the British Film Festival in France, Sienna was back on British shores last night for a book launch in London and had best fashion pal, with Matthew Williamson to accompany her.
The film festival in Dinard, France which saw Sienna on the judging panel, had her making the most of the remaining summer vibes as she showed off a holiday wardrobe stocked full of her own label Twenty8Twelve, including playsuits and nude coloured separates. But last night, back on home shores, the Brit style icon upped the ante as she slipped into a stunning party-perfect gown.
Despite the winter chills already creeping in, Sienna was dressed a season ahead in next one of Matthew's SS11 designs, fresh off the runways.
The rich jewel coloured gown looked made for Sienna who finished the flowing design with tousled locks and the designer on her arm!
With the SS11 designs already making their way onto the red carpet we can't wait to see how our style icons will be styling them.
By Hayley Spencer