Castelo is a Portuguese and Galician surname, derived from the word cognate of Castle. It originates from the term castelo meaning "castle", from Late Latin castellum, and was typically used as a locative surname for someone who lived near a castle or worked within one.Etymology and OriginThe surname Castelo holds deep roots in the Castell and Castillo families, as it is a Portuguese and Galician adaptation of the original meaning. Similar to its Spanish version Castillo and English version Castle, the name was historically given to individuals associated with fortifications, either as residents or as castle staff.Distribution and StatisticsAccording to the 2010 United States Census, Castelo is the 18,899th most common surname in the United States, with approximately 1,445 bearers. It is most prevalent among Hispanic/Latino (65.4%), Asian/Pacific Islander (16.47%), and White (15.22%) individuals, reflecting its ties to Portuguese and Galician communities as well as potential influences in Latin America and Asia through colonization or migration.Cultural and Linguistic NotesThe name exemplifies how toponymic surnames spread across Romance languages. In Galician and Portuguese, the word castelo carries the same meaning as its counterparts in other languages. The surname may also appear in variant forms such as Castell in Catalonia or Castillo in Spain, signifying the shared origin across neighboring territories where castles were central to medieval life and social identity.