Another week, another city. It may have just been New York Fashion Week, but London is already buzzing with the hottest designs to happen across the pond, and, unsurprisingly, some of our favorite celebrities are there to help celebrate — in the front row, no less. Cue Olivia Palermo's never-ending street style savviness, Alexa Chung's love for leopard print, Sienna Miller's continuous sleekness, and Anna Kendrick in one of the sexiest LBDs we've spied in a long time . . . and that's just to name a few. See them all right here, in the gallery.