Isabel Osorio

Isabel Osorio (1522–1589) was a Spanish courtier. She was the long-term royal mistress of King Philip II of Spain.

She was the lady-in-waiting of empress Isabella of Portugal, Joanna of Austria, Princess of Portugal and queen Elisabeth of Valois. She reportedly had two children with Philip. She was rumoured to be married to the king, but this is not believed to have been accurate. She is the subject of a novel, Isabel Osorio: El amor secreto de Felipe II.