Louis XIII (French pronunciation: ​[lwi tʁɛz]; sometimes called the Just; 27 September 1601 – 14 May 1643) was King of France from 1610 until his death in 1643 and King of Navarre (as Louis II) from 1610 to 1620, when the crown of Navarre was merged with the French crown.

Shortly before his ninth birthday, Louis became king of France and Navarre after his father Henry IV was assassinated. His mother, Marie de' Medici, acted as regent during his minority. Mismanagement of the kingdom and ceaseless political intrigues by Marie and her Italian favourites led the young king to take power in 1617 by exiling his mother and executing her followers, including Concino Concini, the most influential Italian at the French court.

Louis XIII, taciturn and suspicious, relied heavily on his chief ministers, first Charles d'Albert, duc de Luynes and then Cardinal Richelieu, to govern the Kingdom of France. The King and the Cardinal are remembered for establishing the Académie française, and ending the revolt of the French nobility. They systematically destroyed the castles of defiant lords, and denounced the use of private violence (dueling, carrying weapons, and maintaining private armies). By the end of the 1620s, Richelieu had established "the royal monopoly of force" as the ruling doctrine. The king's reign was also marked by the struggles against the Huguenots and Habsburg Spain.