Surname Tadamasa (Tadamasa 
, Тадамаса 
) , in all the world, is a very rare cognomen. The cognomen Tadamasa is characteristic of Japan, where it is a very rare surname, Georgia, and China, where it is an extremely rare surname. Much less frequently, Tadamasa is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Tadamasa | Japan, China, Georgia, United States, Brazil |
| Тадамаса | Russia |
| naitō tadamasa (b. 1532) |
|