They’re two of the hottest sisters to hit Hollywood, and last night Hilary Duff and Haylie Duff were spotted enjoying a night out together at the “Project Runway Season 5” finale celebration.

The “War, Inc.” hottie and her “Napoleon Dynamite” starlet sis looked amazing as they arrived at Martell Cognac’s PR shindig, held at Los Angeles eatery STK restaurant.

Hilary went for some classic style with a black and white printed spaghetti strap top with a belted high-waisted black skirt, black stockings, and black heels, while Haylie added some color to the mix with a button-up magenta sweater, black skirt, and yellow heels.

The night before, Hilary was spotted attending the Welcome Home DJ AM shindig, held at the Avalon Club in Hollywood.

Gossip Girls

Enjoy the pictures of Hilary and Haylie Duff at the "project Runway" event last night (October 15).