Fox announced the news on Thursday, revealing that several other alum, including Jordin Sparks, Ruben Studdard, Fantasia, Taylor Hicks and David Cook, will be returning for the star-studded send-off as well.
The original trio of judges, Simon Cowell, Randy Jackson and Paula Abdul, are also set to share some never-before-told stories about the creation of the beloved series and some behind-the-scenes secrets from the first years of the show.
Clarkson made her triumphant return to the Idol stage earlier this season, bringing two of the current judges, Jennifer Lopez and Keith Urban, as well as the in-studio and at-home audiences to tears with a powerhouse performance of her emotional single, "Piece by Piece."
The pregnant singer implied that the February appearance would be her last time on the show when she tweeted, "What an emotional night. Thanks @AmericanIdol for such a beautiful beginning & a perfect ending."
What an emotional night. Thanks @AmericanIdol for such a beautiful beginning & a perfect ending.
Clarkson is quickly approaching her due date, even referencing her pregnancy on-stage last month, but as the original Idol -- she was crowned on season one in 2002 -- it makes sense that we'll see the 33-year-old Texas native in some capacity for the show's massive conclusion after 15 seasons.
American Idol's grand finale kicks off April 5 at 8 p.m. ET/PT with the 90-minute retrospective, American Idol: American Dream. April 6 will see the finalists face off live, and it will be the last chance for fans to vote for the next winner. The very last American Idol will be crowned April 7, at the end of the show's two-hour spectacular.