The young singer, dubbed by judge Simon Cowell "the next Taylor Swift," began writing songs at 3 and used her 11th birthday money to buy a ukulele.
VanderWaal sobbed as her name was announced, and judge Howie Mandel, who granted her entrance into the competition via the golden buzzer, rushed to the stage to hug her.
"You are on your way," Mandel told her. "I love you, you are so special."
She takes home $1 million as part of her grand prize. According to a statement from the show, she will also headline inside the PH Showroom at Planet Hollywood Resort & Casino in Las Vegas on October 27-29.
NBC said the season's finale earned the most votes from the audience in the show's history