Family name Castero (Castero 
) , globally, is a very rare surname. The last name Castero is habitual in Colombia, where it is a very rare surname, Philippines, and Venezuela. In absolute terms, it most frequently occurs in Indonesia, Philippines, and Colombia. Very seldom, Castero is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Castero | Spain, Philippines, Colombia, Indonesia, Venezuela |