Around the world, Castrillo (Castrillo 
) is a very rare male forename. The first name Castrillo is characteristic of Eastern Asia, particularly China, where it is an extremely rare masculine name. More frequently, Castrillo is the last name as well as the forename.
| VARIANT | COUNTRY |
|---|---|
| Castrillo | Colombia, Spain, Nicaragua, Guatemala, Costa Rica |
| gil alamán y garcía castrillo Roman Catholic clergyman (b. 1825) |
|
|
| unknown castrillo, marqués de de benamejí de las cuevas de becerro Peerage person ID=546343 |
|
|
| alonso de castrillo |
|