Fils de France was the style and rank held by the sons of the kings and dauphins of France. A daughter was known as a fille de France.

Dauphin of France, originally Dauphin of Viennois, was the title given to the heir apparent to the throne of France from 1350 to 1791, and from 1824 to 1830. The word dauphin is French for dolphin and was the hereditary title of the ruler of the Dauphiné of Viennois. While early heirs were granted these lands to rule, eventually only the title was granted.