The Frenchman signed a two-year contract and was presented to 10,000 fans at the Stadio Franchi in true Hollywood style.
Ribery will wear the No7 shirt.
“I am very happy to be here," said Ribery in the arena. “I speak some Italian because I like the language and above all Fiorentina!
“I knew three weeks ago that I'd be coming here. Luca Toni is like a brother, he told me to come here because it's a beautiful city."