Spanish Golden Age Culture is an age of secrets and secrecy. Among its playwrights, Pedro Calderón de la Barca shows the most complex comprehension of this subject. During the entirety of his career he refers to it in numerous comedies, creates metaphors concerning different aspects of secrecy and employs it for the construction of his comedias de enredo/comedies of intrigue. In summary: Calderón has an ongoing interest in this anthropological phenomenon. The article analyses the motive of secrecy in selected plays, tragic and comic, starting with the San Secreto figure present in different plays, for example in La vida es sueño. After tracing the temporal aspect of secrecy the article ends with some thoughts about the relation between the public and the secret spheres. Calderón reflects this relation in his masterpiece concerning secrecy: El secreto a voces/The loud secret.