Surname Castañ (Castañ 
) , worldwide, is a rare cognomen. The last name Castañ is habitual in Spain, where it is a rare surname, Colombia, where it is a very rare surname, and Mexico. Likewise, Castañ is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Castañ | Peru, Mexico, Spain, Colombia |