McGraw is to perform for the first time in four years and Gill will sing a duet with the rock band Daughtry, ABC announced.
Other performers added to the lineup include Jason Aldean, Billy Currington, Lady Antebellum, Miranda Lambert and Zac Brown Band.
Brad Paisley and Carrie Underwood are to serve as hosts of the event at the Sommet Center Nov. 11.
Millions of Getty images now available for free via embed tool
NBC reportedly holds celebs hostage to Jimmy Fallon's show