Radu III the Fair, Radu III the Handsome or Radu III the Beautiful (Romanian: Radu cel Frumos), also known by his Turkish name Radu Bey (1435–1475), is the younger brother of Vlad Țepeș and voivode (prince) of the principality of Wallachia.

They are both sons of Vlad II Dracul (Dracul: the dragon) and his wife, Princess Cneajna of Moldavia.

In addition to Vlad Țepeș, Radu also has two older siblings, Mircea II and Vlad Călugărul, both of whom will also briefly rule Wallachia.

Of the four brothers, only Radu converts to Islam and enters Ottoman service.