'Skyscraper' singer Demi, 20, opted for grey skinny jeans and a crisp white shirt with heels for a casual/chic look, while Kelly wowed in a patterned dress and stiletto ankle boots.
The pair joined fellow judges Simon Cowell and Paulina Rubio for the latest round of auditions in Los Angeles on Thursday (11 July).
Former UK X Factor judge Kelly and Latin American singer Paulina joined the show this year, following the departures of Britney Spears and record exec LA Reid.
And it seems like it was a good idea, as Simon has said how well the three women are getting along on the show.
Demi added to The Wrap during an LA press conference: "The whole cast this year, there's something really special about it. And when we come together I feel it's actually a family, which is actually so rare and I feel like it never happens, especially on these shows."
While we're definitely sorry to see Britney and LA go, we're rather excited about the new-look panel.
US X Factor's season two premiere - in pictures:
Copyright: Adriana M. Barraza/WENN.com