Île-de-France (ə-/; French: [il də fʁɑ̃s](listen), literally "Island of France"), often called the région parisienne ("Paris Region") due to containing the city of Paris, is north-central and the most populous of the 18 regions of France. It covers 12,012 square kilometres (4,638 square miles), or two percent of the national territory, and has official estimated population of 12,213,364 as of January 1, 2019, or 18.2% of the population of France. The region accounts for nearly 30 percent of the French Gross Domestic Product (GDP). 
The GDP of the region in 2016 was €681 billion (or $850 billion USD at market exchange rates). It has the highest per-capita GDP among regions in France and the third-highest of regions in the European Union. In 2018, almost all of the twenty-eight French companies listed in the Fortune Global 500 had their headquarters in the Paris Region.
Although the modern name Île-de-France literally means "Island of France", the etymology is in fact unclear. The "island" may refer to the land between the rivers Oise, Marne and Seine, or it may also have been a reference to the Île de la Cité, where the French royal palace and cathedral were located.