The 35-year-old singer reflected on her experience with the Fox reality competition prior to releasing two new singles from her upcoming album, Meaning of Life.
"I do remember [runner-up] Justin [Guarini] and I having the conversation before, because we found out we had to do a movie," Clarkson recalled in an interview with Entertainment Weekly honoring the 15th anniversary of her win.
"He really wanted to do a movie. And I really didn't want to do a movie," she confessed. "I was like, 'It would be super cool if I got second and you got first, because the winner has to do the movie and the second one doesn't."
Clarkson and Guarini ultimately both starred in the 2003 film From Justin to Kelly, which was critically panned and a box office flop. Clarkson told Time in 2015 that she pretends the movie doesn't exist.
"That's what I do," she said. "I just want it to go away. I want to own all of it. I just want it to not be here."
Clarkson released her debut studio album, Thankful, in 2003, after winning American Idol the previous year. She will release Meaning of Life on Oct. 27, and shared a music video for "Love So Soft" and audio for "Move You" on Thursday.
"Ya'll already know!!! #LOVESOSOFT music video!!" the singer announced in a tweet.
In addition to her new album, Clarkson is gearing up to serve as a judge in Season 14 of The Voice. She told EW she chose The Voice over the American Idol reboot because The Voice schedule worked best for her family.