Paris Hilton and boyfriend River Viperi get dressed up for a Halloween house party in Beverly Hills.
Hilary Duff arrives at a Halloween house party in Beverly Hills dressed in a Dia de los Muertos costume.
Hilary Duff and husband Mike Comrie are a spooky pair, arriving in costume for the party.
Julianne Hough and Ryan Seacrest go to the party as Bonnie and Clyde.
Seal arrives at the party with a date.
Emma Roberts dresses as her aunt Julia Roberts in 'Pretty Woman' for Halloween.
Derek Hough is a Jedi!
Alessandra Ambrosio is a sexy general, arriving with husband Jamie Mazur.
Rosie Huntington-Whiteley shows some leg in her costume.
Evan Ross and his girlfriend arrive ready to party.
Celebs Dress Up For A Halloween House Party In Beverly Hills