Fils de France (French pronunciation: [fis də fʁɑ̃s], Son of 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 (French pronunciation: [fij də fʁɑ̃s], Daughter of France).

The children of the dauphin, who was the king's heir apparent, were accorded the same style and status as if they were the king's children instead of his grandchildren.

The king, queen, queen dowager, enfants de France (Children of France) and petits-enfants de France (Grandchildren of France) constituted the famille du roi (Royal Family). More remote legitimate, male-line descendants of France's kings held the designation and rank of princes du sang (Princes of the Blood) or, if legally recognised despite a bar sinister on the escutcheon, they were customarily deemed princes légitimés (Legitimated Princes).

The dauphin, the heir to the French throne, was the most senior of the fils de France and was usually addressed as Monsieur le dauphin. The king's next younger brother, also a fils de France, was known simply as Monsieur, and his wife as Madame.

France (English ⁱ/ˈfræns/ FRANSS or /ˈfrɑːns/ FRAHNSS; French: [fʁɑ̃s] ( listen)), officially the French Republic (French: République française [ʁepyblik fʁɑ̃sɛz]), is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France extends from the Mediterranean Sea to the English Channel and the North Sea, and from the Rhine to the Atlantic Ocean. It is often referred to as l’Hexagone ("The Hexagon") because of the geometric shape of its territory. It is the largest western European country and it possesses the second-largest exclusive economic zone in the world, covering 11,035,000 km² (4,260,000 sq mi), just behind that of the United States (11,351,000 km² / 4,383,000 sq mi).

Over the past 500 years, France has been a major power with strong cultural, economic, military and political influence in Europe and around the world. During the 17th and 18th centuries, France colonised great parts of North America and Southeast Asia; during the 19th and early 20th centuries, France built the second largest colonial empire of the time, including large portions of North, West and Central Africa, Southeast Asia, and many Caribbean and Pacific Islands.