The de Castro surname is used by a Sephardic Jewish family of Portuguese origin. Soon after the establishment of the Portuguese Inquisition, members of the family emigrated to Bordeaux, Bayonne, Hamburg, and various cities in the Netherlands. Their descendants were later to be found scattered throughout Egypt, Madras, France, Germany, Brazil, Italy, the Netherlands, the Philippines, Turkey, Panama, the United Kingdom, and the United States.
Some branches of the family have continued to bear the simple name of de Castro, others are known by de Castro-Osório, de Castro Sarmento, de Castro-Castello-Osório, Pereira de Castro, de Castro Vieira de Pinto, Rodrigues de Castro, Orobio de Castro, de Castro de Paz, Henriques de Castro, etc. The name often appears as "de Crasto." Note that Castro is not in origin Jewish but an Iberian Christian name, adopted by some Portuguese and Spanish Jews after the forced conversions of the late 15th and early 16th centuries.