Rosie Huntington-Whiteley & Julianne Hough: Halloween Party Beauties!

Rosie Huntington-Whiteley dons a flowery headpiece while attending a Halloween party on Friday (October 26) in Beverly Hiils, Calif.

The 25-year-old model turned actress was seen holding onto her pal, fashion expert Nikki Pennie‘s hand.

PHOTOS: Check out the latest pics of Rosie Huntington-Whiteley

At the party, Rosie posted a picture of herself with Derek Hough and tweeted, “Happy Halloween @derekhough @steveshawphoto.” Check out the picture below!

Derek‘s sister Julianne Hough was also spotted at the party with her beau Ryan Seacrest.

Earlier in the week, Rosie and Julianne dressed up for the Samsung Galaxy Launch Party.

20+ pictures inside of Rosie Huntington-Whiteley and Julianne Hough at a Halloween party…