Family name Sixto Alfonso (Sixto Alfonso 
) , in the world, is a very rare cognomen. The last name Sixto Alfonso is habitual in Latin America and the Caribbean, particularly Chile, where it is a very rare surname. More frequently, Sixto Alfonso is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Sixto Alfonso | Ecuador, Chile, Peru, Spain |