Aguilera is hosting the party at TAO in the Venetian. Admission includes entry to the club, open bar and hors d'oeuvres (from 9 to 11 PM).
Richie will be celebrating next door at LAVO in the Palazzo. Partner Joel Madden will be DJing the event where admission also includes entry, drinks and hors d'oeuvres (from 9 to 11 PM). Partygoers will also be able to enjoy the city's New Year's Eve fireworks display from LAVO's terrace.
Aguilera's son Max and Richie's little ones Harlow and Sparrow won't partake in the festivities. Guests must be 21 or older.