Joanna of Navarre (1370? - 1437) was the daughter of Charles the Bad, King of Navarre. She married John V of Brittany, and they had four sons and four daughters. After he died, in 1403 she became the second wife of Henry IV of England. They had no children, but she got on well with his children, often taking the side of the future Henry V of England, "Prince Hal," in his quarrels with his father.

Nevertheless, during the reign of Henry V, she was accused of using witchcraft to try to poison him and imprisoned for about four years in Pevensey Castle in Sussex, England. After that she lived quietly, through Henry V's reign and into that of his son, Henry VI. She is buried in Canterbury Cathedral next to Henry IV.