The term Angevin Empire (; French: Empire Plantagenêt) describes the possessions of the House of Plantagenet during the 12th and 13th centuries, when they ruled over an area covering roughly half of France, all of England, and parts of Ireland and Wales, and had further influence over much of the remaining British Isles. It may be described as an early example of a composite monarchy. The empire was established by Henry II of England, who succeeded his father Geoffrey Plantagenet as Duke of Normandy and Count of Anjou (from which the Angevins derive their name). Henry married Eleanor of Aquitaine in 1152, becoming her royal consort, and inherited his mother Empress Matilda's claim to the English throne, succeeding his rival Stephen in 1154. Although their title of highest rank came from the Kingdom of England, the Plantagenets held court primarily on the continent at Angers in Anjou, and at Chinon in Touraine.

The influence and power of the House of Anjou brought them into conflict with the kings of France of the House of Capet, to whom they also owed feudal homage for their French possessions, bringing in a period of rivalry between the dynasties. Despite the extent of Angevin rule, Henry's son John was defeated in the Anglo-French War (1213–1214) by Philip II of France following the Battle of Bouvines. John lost control of most of his continental possessions, apart from Gascony in southern Aquitaine. This defeat set the scene for further conflicts between England and France, leading up to the Hundred Years' War.