Worldwide, Sergio Alfonso (Sergio Alfonso 
) is quite a rare boy's given name. The forename Sergio Alfonso is habitual in Latin America and the Caribbean, particularly Chile, where it is quite a rare boy's name, Costa Rica, where it is a rare male name, and Peru. Measured by absolute frequency, the name is most common in Chile, Peru, and Spain. Very seldom, Sergio Alfonso is the last name as well as the forename.
| VARIANT | COUNTRY |
|---|---|
| Sergio Alfonso | Peru, Spain, Chile, Mexico, Ecuador |