Worldwide, Тадао (Tadao 
, Тадао 
) is a rare boy's given name. The first name Тадао is habitual in Japan, where it is a rare male name, the United States, where it is a very rare masculine name, and Brazil. In absolute terms, it is the most numerous in Japan, China, and the United States. More frequently, Тадао is the last name as well as the forename.