Salerno is an ancient city and comune (municipality) in Campania, southwestern Italy, and is the capital of the namesake province, being the second largest city in the region by number of inhabitants, after Naples. It is located on the Gulf of Salerno on the Tyrrhenian Sea. In recent history the city hosted Victor Emmanuel III, the King of Italy, who moved from Rome in 1943 after Italy negotiated a peace with the Allies in World War II, making Salerno the capital of the "Government of the South" and therefore provisional government seat for six months. Some of the Allied landings during Operation Avalanche occurred near Salerno.

Campania is an administrative region of Italy; most of it is in the south-western portion of the Italian peninsula, but it also includes the small Phlegraean Islands and the island of Capri. The capital of the Campania region is Naples. As of 2018, the region had a population of around 5,820,000 people, making it Italy's third most populous region, and, with an area of 13,590 km2 (5,247 sq mi), its most densely populated region. 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.