Castillo surname meaning

Castillo is a Spanish place surname built from castillo, “castle” or fortified building. It could identify someone who lived near a castle, worked around one, or came from a locality whose name preserved the landmark. The surname therefore belongs in the place bucket even when a particular family’s records begin far from an actual fortress.

Del Castillo makes the place connection explicit, while Castilho is a Portuguese-related form. Castilla may look connected but is a separate regional name in many records. The useful gloss is architectural and geographic, not a claim of noble descent: ordinary medieval residents could acquire landmark-based surnames. Type place and high confidence fit the shared castle explanation.