Eleanor of Toledo (Italian: Eleonora di Toledo (1522 – 17 December 1562), born Doña Leonor Álvarez de Toledo y Osorio, was a Spanish noblewoman who was Duchess of Florence from 1539, after Margaret of Austria.Although, Eleanor is often referred to as the Grand Duchess of Tuscany, she predeceased the creation of the Grand Duke of Tuscany. She is credited with being the first modern first lady, or consort. She served as regent of Florence during the absence of her spouse.