Beckinsale landed the prestigious Lacoste Spotlight Award for her style choices, but was modest about her win as she accepted her accolade at The Beverly Hilton hotel.
She told the crowd, "Thank you so very much. I'm so honoured and thrilled to be receiving this award. To me, this is an award for being lucky. I'm getting an award tonight for having worked with the best of the best (costume designers)."
Movie legend Clint Eastwood was also honoured, receiving the Distinguished Collaborator Award alongside his longtime on-set designer Deborah Hopper.
Other winners at the ceremony included The Girl With the Dragon Tattoo (Excellence in Contemporary Film), Madonna's royal drama W.E. (Excellence in Period Film), and Harry Potter and the Deathly Hallows: Part 2 (Excellence in Fantasy Film).
Awards were also handed out to the costume designers working on shows including Glee, Boardwalk Empire and Downton Abbey.