Cognomen Ildefonsa (Ildefonsa 
) , around the world, is quite a rare family name. The surname Ildefonsa is habitual in Spain, where it is quite a rare surname, Mexico, and Nicaragua, where it is a rare surname. Also, Ildefonsa is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Ildefonsa | Mexico, Argentina, Peru, Philippines, Spain |