Family name Castillar (Castillar 
) , all over the world, is a rare cognomen. The surname Castillar is habitual in Philippines, where it is a rare surname, Colombia, where it is a very rare surname, and Venezuela, where it is an extremely rare surname. Much less frequently, Castillar is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Castillar | United States, Colombia, Venezuela, Philippines |