Cognomen Udatsu (Udatsu 
) , around the globe, is an extremely rare surname. The family name Udatsu is habitual in New Zealand, where it is a rare surname, and Singapore, where it is a very rare surname. Also, Udatsu is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Udatsu | Singapore, China, New Zealand |