A
- Abogado: a lawyer
- Albacea: an executor of a will
- Alcabala: sales tax
- Alcaide: a warden or commander of a fortress
- Alcalde mayor: a royally appointed official who had administrative and judicial jurisdiction over a community and was subordinate to a governor
- Alcalde ordinario: a judge who had primary (first instance) jurisdiction
- Alférez: the person entrusted with a company's banner
- Alguacil mayor: a royally appointed official who had administrative and judicial jurisdiction over a community or group of communities and was subordinate to a governor
- Almoneda: a public auction of property, often belonging to a deceased person
- Aposentador: billeting officer
- Arras: a gift of a husband to a wife; similar to the dowry
- Artillero: an artilleryman