The Grammy winner is scheduled to perform in New York minutes before the ball in Times Square drops to usher in 2019.
"Surprise Fighters -- we're ringing in the new year together on @NYRE live from Times Square!!!!" Aguilera tweeted Thursday.
Bastille, Dan + Shay and New Kids On The Block are also scheduled to take the stage during the broadcast, which is to kick off at 8 p.m. EST.
Previously announced guests will include Ciara, Camila Cabello, Post Malone, Halsey, Shawn Mendes, Weezer, Kane Brown, Bazzi, Lauren Alaina, The Chainsmokers, Charlie Puth, Kelsea Ballerini, Dua Lipa, Ella Mai, Foster the People, Macklemore and Skylar Grey.