Family name Loin (Leu 
, Loin 
, Lumbus 
) , all over the world, is a common surname. The family name Loin is characteristic of Switzerland, where it is quite a common surname, Liechtenstein, and Moldova (explore the name in all countries). Not in comparison with a country's population, it is the most numerous in Switzerland, Romania, and Germany. Very seldom, Loin is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Leu | Romania, United States, Indonesia, Germany, Switzerland |
| Loin | United States, Malaysia, Indonesia, France, Poland |
| Lumbus | United States, Australia, Philippines, United Kingdom, India |
| Loigne | France |