La Défense (pronounced [la de.fɑ̃s]) is a major business district of the Paris aire urbaine. With a population of 20,000, it is centered in an orbital motorway straddling the Hauts-de-Seine département municipalities of Nanterre, Courbevoie, and Puteaux. The district is at the westernmost extremity of Paris's 10 km long Historical Axis, which starts at the Louvre in Central Paris and continues along the Champs-Élysées, well beyond the Arc de Triomphe before culminating at La Défense.

Around its 110-metre (360 ft)-high Grande Arche and esplanade ("le Parvis"), La Défense holds many of the Paris urban area's tallest high-rises. With its 77.5 acres (314,000 m²), its 72 glass-and-steel slick buildings including 14 high-rises above 150 metres (490 ft), its 180,000 daily workers, and 3.5 million square metres (37.7 million sq ft) of office space, La Défense is Europe's largest purpose-built business district.