Louis I

Louis I may refer to:

* Louis the Pious, Louis I of France, "the Pious" (778–840), king of France and Holy Roman Emperor
* Ludwig I of Thuringia (ruled 1123–1140)
* Louis I of Blois (1172–1205)
* Louis I Wittelsbach, Duke of Bavaria (1173–1231)
* Louis VIII of France who claimed the throne of England as Louis I of England, (1216-1217)
* Louis I, Duke of Bourbon (1279–1342)
* Louis I of Flanders (1304–1346)
* Louis I of Châtillon (died 1346)
* Louis I of Hungary, Louis I of Poland and Hungary, (1326–1382)
* Louis I of Naples (1339–1384)
* Louis of Valois, Duke of Orléans (1372–1407)
* Louis I, Count of Montpensier (1405–1486)
* Louis I de Bourbon, Prince de Condé (1530–1569)
* Louis I, Cardinal of Guise (1527–1578)
* Louis of Spain (1707–1724)
* Ludwig I of Bavaria (1786–1868)
* Luís I of Portugal (1838–1889)