Disney's young adult cable network Freeform will air the full concert live at 2 p.m. EDT on Sunday, while ABC plans a one-hour highlight special following its NBA Finals telecast. The concert will also be broadcast on more than 130 iHeartRadio stations.
Grande will be joined by the Black Eyed Peas, Robbie Williams, Justin Bieber, Katy Perry, Miley Cyrus, Coldplay and other stars.
The May 22 attack at a Grande concert killed 22 people and injured dozens more.
Proceeds will go to an emergency fund set up by the city of Manchester and the British Red Cross.