Cognomen Eisaku (Eisaku 
) , throughout the world, is a rare family name. The family name Eisaku is habitual in Japan, where it is a rare surname, Singapore, where it is a very rare surname, and Malaysia, where it is an extremely rare surname. Measured by absolute frequency, this name is the most popular in Japan, China, and Singapore. Much less frequently, Eisaku is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Eisaku | Japan, Brazil, China, United States, Singapore |