Last name Ониши (Onishi 
, Ониши 
) , around the globe, is quite a rare cognomen. The family name Ониши is characteristic of Paraguay, where it is quite a rare surname, Bolivia, and Taiwan, where it is a rare surname. Measured by absolute frequency, it is commonest in Brazil, Japan, and the United States. Very seldom, Ониши is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Onishi | China, Brazil, United States, Taiwan, Japan |
| Ониши | Russia |