<Tr> <Td_colspan="2"> <Ul> <Li> ◀ </Li> <Li> 2005 </Li> <Li> ▶ </Li> </Ul> </Td> </Tr> <Ul> <Li> ◀ </Li> <Li> 2005 </Li> <Li> ▶ </Li> </Ul> <P> The fourth season of American Idol premiered on January 18, 2005 and continued until May 25, 2005 . It was hosted by Ryan Seacrest . Randy Jackson, Paula Abdul and Simon Cowell also returned to judge . Carrie Underwood won the season with approximately 500 million votes cast in the season and 37 million for the finale . Underwood has since gone on to become a seven - time Grammy - winning country megastar . </P> <P> While in the past seasons celebrity guest judges have been invited to participate during the competition, this was the first season where guest judges were invited to participate in the auditions . The music celebrities featured were: </P>

Who won carrie underwood season of american idol