Last name Йустин (Justin 
, Yustin 
, Iustin 
) , in the entire world, is a common cognomen. The family name Йустин is characteristic of Saint Lucia, where it is a common surname, Brunei, where it is quite a common surname, and Slovenia (explore the name in all countries). Measured by absolute frequency, it is the most numerous in Nigeria, Indonesia, and Cameroon. More prevalently, Йустин is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Justin | Myanmar, Cameroon, Australia, United States, Democratic Republic of the Congo |
| Yustin | Tanzania, South Africa, Indonesia, United States, Malaysia |
| Iustin | Indonesia, United States, United Kingdom, Germany, Canada |
| Йустин | Russia |