Pernice and Guaccero, who is an actress and singer, won the 19th season of Ballando Con Le Stelle after performing dances including the Argentine Tango and the Charleston.
The pair had recently confirmed their status as a romantic couple.
Italian-born Pernice shared several posts on Instagram about his win and thanked UK fans for their support.
The BBC apologised to Pernice’s former partner Amanda Abbington in September. Abbington, who played Mary Morstan in Sherlock, has since said she felt vindicated and that she had “no regrets” after making the complaints.
In response to the BBC’s findings, Pernice said he was “relieved” allegations he was threatening and abusive were found not to be true.
He said he was a “strict teacher” but not a bully in a TV interview in October, admitting frustration is commonplace for both contestants and the professionals with the pressure “to perform perfectly on the Saturday night”.