Love birds Alex and Sierra were named the winners of X Factor's season 3 on Thursday and their disbelief was easy to acknowledge.

"We're speechless. I don't even know. This is incredible. Thank you everybody that's voted," Alex Kinsey said after the couple was crowned.

Sierra Deaton added: "Thank you so much for getting us here and thanks for not making fun of my weird faces all of the time."

After their win, the pair even had trouble getting through their final performance on the show. As Alex started singing A Great Big World's Say Something, he broke down in tears.

The Florida natives, who were mentored by Simon Cowell throughout the season, will now receive a million dollar recording contract with Sony Music.

Scroll through the gallery above to see photos of the couple even before they were famous.