Harding, 30, was coming out of The Dorchester Hotel when she was caught off guard by fans, who had camped outside to get a glimpse of the Kardashian sisters - Kim, Khloe, Kourtney - and were thrilled to see her, reported Daily Mail online.
The Kardashian sisters had made the hotel their base while promoting their new clothing range - Kardashian Kollection.
Even though she looked unprepared for the chaotic scenes that greeted her when she left the hotel, Harding looked overwhelmed but pleased as she chatted to a small group of fans who approached her to ask for an autograph.