Underwood, who's now serving as a judge on the show, won the show in 2005 Carrie Underwood is throwing it back to 2005. On Sunday, April 6, the "Before He Cheats" singer shared a carousel of never-before-seen pictures from her run on American Idol in 2005.

Underwood won Season 4 of the singing competition show in 2005, and recently returned for Season 23 as a judge.

During Monday's episode of "American Idol," Carrie Underwood shared a heartfelt testimony after contestants went head-to-head during a performance of Brandon Lake's "Gratitude."