Cognomen Будаи (Budai 
, Buday 
, Boudai 
) , globally, is a common last name. The last name Будаи is characteristic of Eastern Europe, particularly Hungary, where it is a common surname, Slovakia, where it is quite a common surname, and Romania. Not in comparison with a country's population, this name is the most popular in Hungary, Romania, and Philippines. Also, Будаи is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Budai | Romania, Hungary, Philippines, India, Japan |
| Buday | Romania, Hungary, Philippines, Slovakia, India |
| Boudai | Kuwait, France, United States, India, Algeria |
| Будаи | Russia |