The Coronation Street actor beat theatre star Jodie Prenger to be crowned this year's winner of the BBC dance series.
Cotton received the most votes from the public after his tap dancing performance of 'Anything Goes'.
Judge Frank Skinner quipped after his performance: "It was right up my 42nd Street."
Skinner, Jo Brand and Greg Davies judged the final and gave unanimous praise to all the finalists.
Prenger came second with her performance of 1986 Cameo hit 'Word Up', in which the actress dressed as the funk group's frontman Larry Blackmon.
The other finalists were Tim Vine, The Soapstars, Katherine Ryan and Lee Nelson.
Cotton follows in the footsteps of previous winners Robert Webb, Rufus Hound, Charlie Baker and James Thornton and Rowland Rivron. Rivron won the 2012 series with his performance to Fatboy Slim's 'Weapon of Choice'.
The series has raised over £1 million for this year's Comic Relief.
The final in pictures