Fiorentino Rossi is the second eldest of the three Rossi brothers. He was once a mandolier and a lover of the Duchessa. After retiring at age twenty-five, as all mandoliers must do by law, he used the large pension given to him by the Duchessa to open restaurant on the Piazza Maddalena. The restaurant, Fiorentino's, began modestly but eventually grew to become one of the best restaurants in Bellezza.
Neither Fiorentino nor Egidio ever married, likely because they had been the Duchessa's former lovers and remain devoted to her. The Rossi brothers live across from one another, with a bridge over a canal connecting their residences. At the request of the Duchessa, they take in Guido Parola and teach him how to be a mandolier. In the epilogue of City of Masks, Fiorentino and Egidio praise their niece's sculling skills and later appear with Guido at the new Duchessa's ball for Carnivale.