Joan I
Joan I or Joanna I may refer to:
- Joan I, Countess of Burgundy
- Joan I of Navarre, daughter of King Henry I of Navarre and Blanche of Artois
- Joan I, Countess of Auvergne
- Joanna I of Naples
- Joan I, Countess of Dreux, only child of Peter, Count of Dreux
- Joanna of Castile, a.k.a. Joanna I or Juana I, Queen of Castile and Aragon, daughter of Isabella I of Castile and Ferdinand II of Aragon