Carrie Underwood marks 15th anniversary of her 'American Idol' win

She won season 4 of the iconic singing competition show in 2005.

Monday marked 15 years since Carrie Underwood’s "American Idol" win, and the country superstar celebrated the anniversary by sharing a video put together by one of her fans.

"WOW, I cannot believe it’s been 15 years since my @americanidol win!!!" Underwood, who beat runner-up Bo Bice in the 2005 season 4 finale, tweeted in a response to the YouTube clip, titled "Happy 15th 'Idol-versary' Carrie."

"It’s been an incredible ride and I couldn’t have made it through without all of you guys!!" the Oklahoma native added. "THANK YOU so much for this sweet video!!"

The clip starts off with "American Idol" host Ryan Seacrest announcing her as the season 4 champ, followed by a montage of Underwood's fans congratulating her on the anniversary and sharing touching stories of the impact she has had on their lives.

Since winning "Idol," the 37-year-old has become one of the show's most successful alumni. Her debut single, "Inside Your Heaven," made her the only country artist to debut at No. 1 on the Billboard Hot 100 and the only solo country artist in the 2000s to top the Hot 100.

On top of that, she has also won seven Grammys and has become one of the bestselling female artists of all time.