The surname "Mendes" is of Portuguese and Spanish origin, often derived from the given name "Mendo," which means "to be strong." It is a common surname in countries with Portuguese and Spanish influence, including Brazil, Portugal, and Spain. Mendes can also be found among Jewish communities, particularly among Sephardic Jews, who adopted the surname after the expulsion from Spain in the late 15th century. The name has various spellings and forms, such as "Mendès" or "Mendizabal," reflecting regional variations and cultural influences.