Last name Гаина (Gaina 
, Gayna 
, Гаина 
) , globally, is quite a common cognomen. The cognomen Гаина is habitual in Marshall Islands, where it is quite a common surname, Moldova, and Romania. Not in comparison with a country's population, this name is the most popular in Romania, India, and Moldova. Likewise, Гаина is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Gaina | Democratic Republic of the Congo, Moldova, Romania, Italy, India |
| Gayna | Democratic Republic of the Congo, United Kingdom, United States, Malaysia, India |
| Гаина | Ukraine, Kyrgyzstan, Russia, Kazakhstan |