Since then, Clarkson, 27, has been in the limelight, collecting a cachet of Grammys, American Music Awards, and MTV Video Music Awards. She's also been nominated for a Country Music Award. Now, she's promoting her fourth album, "All I Ever Wanted," released this year.
That's the public side, but what about the private side? Here are 10 things you might not know about the first American Idol:
1. Kelly's new hobby is golf.
2. Before appearing on "American Idol," Kelly's Los Angeles apartment was destroyed by a fire.
3. Kelly owns a variety of pets, including some rescued dogs from Hurricane Katrina.
4. An avid reader, Kelly says her favorite book is "Jane Eyre" by Charlotte Bronte.
5. Kelly loves board games.
6. Kelly does not Twitter.
7. Kelly covers the Rod Stewart song "Some Guys Have All the Luck," but she's changed it to "Some Girls Have All the Luck" on her current tour.
8. At 16, Kelly wrote "Because of You."
9. Kelly is a big fan of Meryl Streep, and her favorite Streep movie is "Sophie's Choice."
10. Kelly sometimes records in her bathroom closet.