Surname นิชิอิ (Nishii 
, นิชิอิ 
) , worldwide, is a rare last name. The last name นิชิอิ is characteristic of Taiwan, where it is a rare surname, Estonia, and Japan. Measured by absolute frequency, it is commonest in Taiwan, Japan, and the United States. Very seldom, นิชิอิ is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Nishii | China, United States, Peru, Taiwan, Japan |
| นิชิอิ | Thailand |