Last name Ustinia (Устинья 
, Устиня , Ustinia 
) , in the entire world, is a very rare surname. The last name Ustinia is habitual in Kyrgyzstan, where it is a very rare surname, Georgia, and Russia, where it is an extremely rare surname. Much more frequently, Ustinia is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Устинья | Kazakhstan, Belarus, Kyrgyzstan, Russia, Ukraine |
| Устиня | Russia, Kazakhstan, Ukraine |
| Ustinia | Brazil, Romania, Venezuela, Georgia |