The pair secured the coveted Glitterball trophy after receiving the most public votes in the grand final.
Waterloo Road actress Chelsee Healey and partner Pasha Kovalev finished in second place.
Judd's McFly bandmates Tom Fletcher, Dougie Poynter and Danny Jones stormed the stage to congratulate him following the announcement, but were quickly ushered away by Bruce Forsyth.
"All I can say is thank you from the bottom of my heart to everyone who has supported Aliona and I," Judd said of his win. "I have had the most incredible experience, thank you.
"I've been on the best show on TV and I'm just honoured. I was so nervous when I first started, I didn't think I'd be able to do it, but Aliona has got me through it."
Both couples had earlier performed a dance of the judges' choice, as well as a showdance and a dance they hadn't attempted before.
For his final dance, Judd performed the Argentine Tango and received a perfect score of 40 from the judges, taking his total for the evening to 156.
Healey and Kovalev fell short of a perfect score for their final performance, securing 39 points to give them a total of 153.
Jason Donovan and Kristina Rihanoff finished in third place earlier on in the evening.
Judd and Vilani were congratulated by their fellow contestants, before closing the show with a dance to 'Simply The Best'.
Digital Spy readers correctly predicted the order of this year's top three Strictly finalists.
> Strictly Come Dancing 2011 final - Harry Judd's win in pictures
Watch Harry and Aliona's showdance below: