She looked gorgeous wearing a silver spiked Marco Marco shoulder dress and partied with guests Derek Hough, Tiffany Thornton and Hunter Parrish.
There was no alcohol at Demi's party, but there was an open Red Bull bar. She danced and mingled with pals all night - and even cut into her huge birthday cake, which was shaped like a skyscraper.
Sounds like a FAB party, D! It's a new age, a new year, and a whole new you! Happy Birthday!
[Image via WENN.]