Cognomen Таддеи (Taddei 
, Таддеи 
, Taddeï ) , across the world, is quite a common family name. The family name Таддеи is habitual in San Marino, where it is a common surname, British Virgin Islands, where it is quite a common surname, and Italy, where it is quite a rare surname. Measured by absolute frequency, the name is most common in Italy, France, and the United States. Very seldom, Таддеи is the forename as well as the last name.