Family name ปิ่นฤทัย (Pinruthai 
, Pinrutai , Pinruethai 
) , all around the world, is a very rare surname. The family name ปิ่นฤทัย is habitual in Thailand, where it is a very rare surname, and the United States, where it is an extremely rare surname. More frequently, ปิ่นฤทัย is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Pinrutai, Pinruthai | Thailand |
| Pinruethai | United States, Thailand |