Carrie Underwood gave fans a blast from the past by performing "Alone" on "American Idol," two decades after doing so on the show in 2005.

“American Idol” judge Carrie Underwood has surprised viewers with a callback to her time on the show in 2005.

Carrie Underwood reunited with other former 'Idol' contestants from the show's fourth season in 2005. Here's what they said ...

Carrie Underwood, 42, went back to her “American Idol” roots for the season’s “iconic Idol moments” special on Monday night.

There were enough hints dropped by American Idol regarding this nostalgic performance, but still, it took fans by surprise.

Longtime American Idol viewers undoubtedly recognized the dress Carrie Underwood wore on the show on Monday night (April 28).

Days after she shared a 20-year-old clip of her performing Heart’s hit 'Alone,' she opened the show’s Rock and Roll Hall of ...

It’s been 20 years since Carrie Underwood won Season 4 of American Idol in 2005, but she can still fit into the same exact ...

Carrie Underwood's choice of dress for the American Idol finale is turning heads. The judge wowed audiences when she slipped ...

Carrie Underwood‘s cover of Heart’s “Alone” on American Idol is now one of the most memorable performances from her winning ...

Carrie Underwood has come full circle since winning "American Idol" two decades ago. The singer has sold over 85 million ...

The theme of tonight's episode of American Idol is "Rock and Roll Hall of Fame Night," and judge Carrie Underwood is ready to ...