"It's amazing to me to think that so many people voted for me like that, you know, to make me the next American Idol," Thompson said. "I did not expect this experience to end up this way, so, I'm blown away man."
The three finalists sang the music of Bruce Springsteen in a bid to win the title.
HunterGirl came in second place in the competition, and Leah Marlene came in third.
WATCH: American Idol' winner Noah Thompson on what he plans to do now
Thompson, Marlene, and HunterGirl were good enough to impress the judges all season long, and in fact, it's fair to say the trio got them excited from the very start.
Sunday's finale was like a free concert. The contestants, the judges and some big names in music performed in a 3-hour, music-filled celebration.
Among the many musical guests: Earth, Wind and Fire, Melissa Etheridge, Flo Rida and Michael Bublé.
Carrie Underwood was scheduled to perform at Sunday's finale but was unable to do so.
"There was a COVID exposure within Carrie Underwood's group," host Ryan Seacrest said at the beginning of the show. "So following protocol, she's unable to perform tonight. Sad, but you can check her out on her tour, Denim & Rhinestones. That tour coming this fall, OK. So, go see her."
Win or lose, all three finalists called their time on "American Idol" a life-changing experience.
"I came into the show and I never know what to expect, but I know I'm going to leave with so much experience, so many people I'm going to talk with for the rest of my life," HunterGirl said.
Finalist Leah Marlene says that she loves the energy of a live audience. For her, this whole experience was one big celebration.
"Music is all about sharing a moment with other people and so, like, to have people to feed off of, like, that's what it's all about, is to enjoy it together and be in it together," Marlene said.
At 19 years old, Noah Thompson is the youngest of the three.
"I remember walking in, seeing the judges. Man, I was scared out of my mind," Thompson said. "I've never been so nervous in my life, you know? But now, the people is what literally brings that life out of you."
"American Idol" is coming back for season 21.