Hilton, who wore a nude sequin-encrusted mini-dress, boasted via Twitter that the February 16 bash was "the most beautiful, amazing, extravagant birthday party ever" and the most fun she's "ever had in my entire life."
A source said that "everyone was given a mask" upon their arrival, including A-list guests like Chace Crawford, Stephen Dorff and Emile Hirsch, reported Us magazine.
Hilton's parents, Rick and Kathy, joined in on the fun, as did her handbag designer sister Nicky, 28.
Hip-hop couple Wiz Khalifa, 24, and Amber Rose, 28, danced as Hilton's beau, DJ Afrojack, and her friend, DJ Mr Best, played the hotel heiress' favorite songs.
Once the bash ended, Hilton and pals continued to celebrate until the wee hours of the morning. "The after party went on until 7 am," the source said.