Campania is an administrative region of Italy, located in the south of the country; most of it is in the southwestern portion of the Italian Peninsula (with the Tyrrhenian Sea to its west), but it also includes the small Phlegraean Islands and the island of Capri. The capital is Naples. Campania has a population of 5,575,025 as of 2025, making it Italy's third-most populous region, and, with an area of 13,590 km (5,247 sq mi), its most densely populated. Based on its GDP, Campania is also the most economically productive region in Southern Italy and the 7th most productive in the whole country. Naples' urban area, which is in Campania, is the eighth most populous in the European Union. The region is home to 10 of the 58 UNESCO sites in Italy, including Pompeii and Herculaneum, the Royal Palace of Caserta, the Amalfi Coast, the Longobardian Church of Santa Sofia in Benevento, and the Historic Centre of Naples. In addition, Campania's Mount Vesuvius is part of the UNESCO World Network of Biosphere Reserves. The region plays a key international role in international diplomacy, since it is home to NATO's Allied Joint Force Command Naples and the Parliamentary Assembly of the Mediterranean.
The Campania's hinterland was inhabited from the beginning of the 1st millennium BC by the Osci, Samnites, and Etruscans, while between the 8th and 7th centuries BC its coastal areas were colonised by the ancient Greeks (Magna Graecia). At that time, Capua was Campania's leading city, while Naples was an anomaly, being predominantly Greek-speaking.