The US classical singer, who sold more than 5 million copies of his 2007 Christmas album Noel, said that he is very "excited" to be a part of the Australian festive celebrations.
Groban told AAP: "It sounds like the perfect venue for me to sing this music and I'm very, very excited about it. It's wonderful when you feel like you can sing your songs that you've poured your heart and soul into in front of some amazing fans in a show that people really love."
Other acts include country singers Troy Cassar-Daley and Felicity Urquhart, children's entertainers The Wiggles, Australian Idol winner Stan Walker and Australia's Got Talent stars Justice Crew.
The event takes place on December 18.