Cognomen Santillàn (Santillàn 
) , across the world, is a very rare surname. The surname Santillàn is habitual in Latin America and the Caribbean, particularly Argentina, where it is a very rare surname, Ecuador, and Peru. Measured by absolute frequency, it is the most numerous in Latin America and the Caribbean, particularly Mexico, Argentina, and Peru.
| VARIANT | COUNTRY |
|---|---|
| Santillàn | Peru, Mexico, Argentina, Ecuador |