Carey plays an aspiring pop singer in Glitter
The singer will appear and perform as part of a telethon in aid of families of victims of last week's attacks on the US.
In July, 31-year-old Carey checked herself into hospital suffering from "extreme exhaustion" and suffered a relapse in September.
But she is now back on form and a publicist said she is expected to sing the song Hero.
In a rare collaboration between US television networks, seven commercial stations will broadcast the Friday evening show called America: A Tribute to Heroes.
Bruce Springsteen, the Dixie Chicks, Stevie Wonder and Paul Simon are among the names also to take part.
They will be joined by actors including Jim Carrey, George Clooney, Tom Cruise, Tom Hanks and Julia Roberts.
The show will raise money through telephone and online pledge donations for US victims of last week's attack on the World Trade Center and Pentagon.
This will be Carey's first performance since the Grammy-award winner was forced to cancel all appearances during the summer.
There were rumours that she had attempted suicide, which were subsequently denied by her publicist.
Her spokeswoman said that she suffered an "emotional and physical breakdown", as a consequence of working too hard and not getting enough sleep.
Her movie - Glitter - was also postponed.
Glitter is Carey's first starring role. She plays an aspiring pop singer and is also one of the film's producers.
Carey was raised by her mother, a former opera singer and began singing at the age of four.
She began to write songs while she was at school and soon after graduation had broken into the recording industry, making her debut on Columbia Records in 1990.
She was the biggest-selling artist of the 90s and is best known for hits I'll Be There, Without You, Fantasy and Open Arms.
Her single Heartbreaker made her one of the most successful artists ever in 1999, when it became her 14th American number one single, a feat rivalled only by the Beatles (20) and Elvis Presley (17).