Taddea Malaspina (1505 - ?) was an Italian marchesa. She was the mistress of Alessandro de' Medici, Duke of Florence from the early 1530s to about 1537 and was likely the mother of at least two of his children, Giulio di Alessandro de' Medici and Giulia de' Medici. Giulio de' Medici was associated with the Malaspina family at different points throughout his life. Taddea was the younger daughter of Alberico Malaspina, sovereign marquis of Massa, and Lucrezia d'Este. She married Count Giambattista Boiardo di Scandiano. After his death and the death of her father, Malaspina lived with her mother in Florence and had a number of lovers, including Alessandro. Her sister Ricciarda inherited the title after their father's death. Through Ricciarda's marriage, the family was related to Pope Innocent VIII. Ricciarda was probably also one of Alessandro de' Medici's lovers.
In a portrait of Alessandro by Pontormo, dated to about 1534, the Duke, dressed in black, draws the profile of a woman in silverpoint. The portrait may have been a gift for Malaspina. The Chiesa della Madonna del Carmine and the Santa Chiara monastic complex in Massa, now in the Italian province of Massa Carrara, were built on Taddea Malaspina's order; they still stand.
- Ricciarda Malaspina, Taddea's sister