Ridolfo "Aristotele" Fioravant (born c. 1415 or 1420) was an architect and a member of the Italian Brotherhood of Assassins during the 15th century. He was sent as a spy to Moscow, where he was hired to work on the Kremlin alongside fellow Assassin Pietro Antonio Solari.
After the death of Solari in May of 1493 by Tsar Ivan III's men, Ridolfo was blamed with his death. He faked his own death and fled.
In 1503, Ezio Auditore da Firenze sent his apprentices to Moscow to discover the truth. The Assassins found Ridolfo and took him to the Assassins' headquarters in Rome, where he was questioned. During this, Aristotele revealed that Ivan knew that he and Solari were spies.
He believed he was close to uncovering a major conspiracy. Ezio sent his Assassins back to Moscow, assigned with planting evidence linking the two architects to the Strigolniki Sect. After the death of his two top investigators, Ivan believed their deaths to be linked to the religious cult.