Family name ข้อย (Khoi 
, ข้อย) , across the world, is quite a rare surname. The cognomen ข้อย is habitual in Malaysia, where it is quite a rare surname, Vietnam, and Taiwan, where it is a rare surname. Measured by absolute frequency, the name is most common in South-eastern Asia, particularly Vietnam, Malaysia, and Indonesia. More frequently, ข้อย is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Khoi | Malaysia, Indonesia, India, Vietnam, United States |