Reggio di Calabria (Southern Calabrian: Riggiu; Calabrian Greek: Ρήγι, romanized: Rìji), usually referred to as Reggio Calabria, or simply Reggio by its inhabitants, is the largest city in Calabria as well as the seat of the Regional Council of Calabria. It has an estimated population of nearly 200,000 and is the twenty-first most populous city in Italy, after Modena, and the 100th most populated city in Europe. Reggio Calabria is located in the exact center of the Mediterranean and is known for its climate, ethnic and cultural diversity. It is the third economic centre of mainland Southern Italy. About 560,000 people live in the metropolitan area, recognised in 2015 by Italy as a metropolitan city.

Reggio is located on the "toe" of the Italian Peninsula and is separated from the island of Sicily by the Strait of Messina. It is situated on the slopes of the Aspromonte, a long, craggy mountain range that runs up through the centre of the region.

As a major functional pole in the region, it has strong historical, cultural and economic ties with the city of Messina, which lies across the strait in Sicily, forming a metro city of less than 1 million people.

Reggio is the oldest city in the region, and during ancient times, it was an important and flourishing colony of Magna Graecia. Reggio has a modern urban system, set up after the catastrophic earthquake of 1908, which destroyed most of the city. Before that seismic event, the region has been subject to several other previous earthquakes. The seismicity is caused by Reggio being on the Eurasian Plate near the faultline where it meets the African Plate that runs through the strait, dividing the two European regions of Calabria and Sicily into two different tectonic regions.

It is a major economic centre for regional services and transport on the southern shores of the Mediterranean. Reggio, with Naples and Taranto, is home to one of the most important archaeological museums, the prestigious National Archaeological Museum of Magna Græcia, dedicated to Ancient Greece (which houses the Bronzes of Riace, rare example of Greek bronze sculpture, which became one of the symbols of the city). Reggio is the seat, since 1907, of the Archeological Superintendence of Bruttium and Lucania. The city is home to football club Reggina, that previously played in the Italian top flight.

The city centre, consisting primarily of Liberty buildings, has a linear development along the coast with parallel streets, and the promenade is dotted with rare magnolias and exotic palms. Reggio has commonly used popular nicknames: The "city of Bronzes", after the Bronzes of Riace that are testimonials of its Greek origins; the "city of bergamot", which is exclusively cultivated in the region; and the "city of Fatamorgana", an optical phenomenon visible in Italy only from the Reggio seaside.