About the Castrillo Surname

Castrillo is best understood alongside Castro: both are Spanish spellings of one family name.

Local scribes, dialects and emigration all left their mark on how the name was written. With the diminutive -illo, Castrillo is an affectionate form of Castro that became a surname in its own right.

A coat of arms belongs to a particular family line rather than to everyone named Castrillo, so the heraldry linked to Castro is a starting point, not an automatic right. Research your Castrillo family history with a full surname report and painted coat of arms.