oidor

thumb|A portrait of Diego del Corral y Arellano, of the Council of Castile, by the painter Diego Velázquez

An '''' () was a judge of the Royal Audiencias and Chancillerías'', originally courts of Kingdom of Castile, which became the highest organs of justice within the Spanish Empire. The term comes , referring to the judge's obligation to listen to the parts of a judicial process, particularly during the phase of pleas.