Louis

French form of Ludovicus, the Latinized form of Ludwig. It was the name of 18 kings of France, beginning with Louis I, son of Charlemagne, and notable rulers include Louis IX (Saint Louis), who led two crusades, and Louis XIV, the Sun King, who ruled at the height of French power, built the Palace of Versailles, and became the longest-reigning monarch in European history. The name was also used by kings of Germany as Ludwig, of Hungary as Lajos, and elsewhere. In France it was only moderately popular outside royalty during the Middle Ages, and it declined after the French Revolution, when Louis XVI was guillotined. The Normans brought it to England, where it was usually spelled Lewis, though Louis has been more common in America. Famous bearers include the French scientist Louis Pasteur, the actor Louis de Funès, the Scottish writer Robert Louis Stevenson, and the American jazz musician Louis Armstrong.

Louis moved from #236 to #249 for boys between 2024 and 2025. Its highest annual birth count came in 1921, with 7,247 births.