Joanna of Austria, Grand Duchess of Tuscany, Austrian Archduchess (d. 1578)
Joanna of Austria (German Johanna von Österreich, Italian Giovanna d'Austria) (24 January 1547 – 11 April 1578) was an Archduchess of Austria. By marriage, she was the Grand Princess of Tuscany and later the Grand Duchess of Tuscany. One of her daughters was Marie de' Medici, second wife of King Henry IV of France.