Alex & Sierra are an American pop duo consisting of Alex Kinsey (born September 8, 1991) and Sierra Deaton (born February 11, 1991), who won the third and final season of The X Factor USA. They were mentored by Simon Cowell and became the first and only group to win the American version of the show. Show more...

Alex & Sierra are an American pop duo consisting of Alex Kinsey (born September 8, 1991) and Sierra Deaton (born February 11, 1991), who won the third and final season of The X Factor USA. They were mentored by Simon Cowell and became the first and only group to win the American version of the show.