Cartagena is a Spanish city and a major naval station located by the Mediterranean coast, south-eastern Spain. As of January 2011, it has a population of 218,210 inhabitants being the Region's second largest municipality and the country's 6th non-Province capital city.

Cartagena has been inhabited for over two millennia, being founded around 227 BC by the Carthaginian Hasdrubal the Fair as Qart Hadasht. The city lived its heyday during the Roman Empire, when it was known as Carthago Nova (the New Carthage) and Carthago Spartaria, capital of the province of Carthaginensis. It was one of the important cities during the Umayyad invasion of Hispania, under its Arabic name of Qartayannat al-Halfa.

Much of the historical weight of Cartagena in the past goes to its coveted defensive port, one of the most important in the western Mediterranean. Cartagena has been the capital of the Spanish Navy's Maritime Department of the Mediterranean since the arrival of the Spanish Bourbons in the 18th century. As far back as the 16th century it was one of the most important naval ports in Spain, together with Ferrol in the North. It is still an important naval seaport, the main military haven of Spain, and is home to a large naval shipyard.

The confluence of civilizations as well as its strategic harbour, together the rise of the local mining industry is manifested by a unique artistic heritage, with a number of landmarks such as the Roman Theatre, the second largest of the Iberian Peninsula after the one in Mérida, an abundance of Phoenician, Roman, Byzantine and Moorish remains, and a plethora of Art Nouveau buildings, a result of the bourgeoisie from the early 20th century. Cartagena is now established as a major cruiser destination in the Mediterranean and an emerging cultural focus.

It is the first of a number of cities which eventually have been named Cartagena, most notably Cartagena de Indias (Cartagena of the Indies) in Colombia.