The concert is to premiere exclusively on the cable network Dec. 17, with Ellen DeGeneres serving as host.
Bocelli will be performing selections from his double platinum CD, "My Christmas." He is the latest addition to a show that will also feature Mariah Carey, Miranda Cosgrove, Annie Lennox, Maxwell and Matthew Morrison, TNT said.
U.S. President Barack Obama and first lady Michelle Obama are expected to attend the event, along with other Washington luminaries.
The holiday musical celebration, which is to benefit the Children's National Medical Center, will be taped at the National Building Museum in Washington Dec. 12.