After receiving the majority of the public vote, she beat 17-year-old Sophie Evans in tonight's live final on BBC One.
Danielle and Sophie, who both had to perform renditions of 'Over The Rainbow' as well as their favourite songs from the series, were lauded by the judges and Andrew Lloyd Webber for their performances throughout the competition.
Upon her victory, Danielle said: "I really, really don't think a thank you is enough. For the amazing public and everyone who comes to support us every week and the girls. Thank you and it comes from [the heart] and we all [thank you] for this amazing opportunity."
Lord Webber commented: "The nation hasn't got it wrong yet. My goodness me, you can act from the soul, and that's very, very special."
Danielle's cover of Judy Garland's iconic 'Over The Rainbow' is on sale now, and the star will appear on the Royal Variety Performance later this year.