Family name Leoncio Fermin (Leoncio Fermin 
) , in the world, is an extremely rare last name. The surname Leoncio Fermin is habitual in Latin America and the Caribbean, particularly Chile, where it is an extremely rare surname. Much more frequently, Leoncio Fermin is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Leoncio Fermin | Chile, Argentina, Peru, Ecuador |