Credit: Dave M. Benett/Getty; Flynet; Eamonn McCormack/WireImage

Last weekend, a mix of British and American stars and socialites headed to Surrey, England to celebrate at Cartier's International Polo Party. And we love seeing them in their summertime best! Both Cat Deeley (who is always fashion-forward on SYTYCD) and Leslie Mann opted to wear flowing, printed designs (Deeley's was vintage, Mann's Louis Vuitton) to the polo match, while Camilla Belle kept things crisp in white (with just a dash of color). Geri Halliwell broke the party's casual fashion mold by sporting a skin-tight, figure-flattering Herve Leger minidress. The highlight of the event (besides the match)? The traditional afternoon tea, of course.

See more from this week's hottest parties.