Madrid (pronounced 1 in English, 2 in Spanish and colloquially in Spain 3) is the capital and largest city of Spain. It is the third-most populous municipality in the European Union after London and Berlin, and the fourth-most populous urban area in the European Union after Paris, London, and the Ruhr Area.

The city is located on the river Manzanares both in the centre of the country and Community of Madrid (which comprises the city of Madrid, its subsequent conurbation and extended suburbs and villages); this community is bordered by the autonomous communities of Castile and León and Castile-La Mancha. As the capital city of Spain, seat of government, and residence of the Spanish monarch, Madrid is also the political center of Spain. The current mayor is Alberto Ruiz-Gallardón from the center-right People's Party. He has been in office since 2003, when he left the Presidency of the Autonomous Community of Madrid and stood as the candidate to replace outgoing mayor José María Álvarez del Manzano, also from the PP. In the last local elections of 2007, Ruiz-Gallardón increased the PP majority in the City Council to 34 seats out of 57, taking 55.5% of the popular vote and winning in all but two districts.

Due to its economic output, standard of living, and market size, Madrid is considered the major financial center of the Iberian Peninsula; it hosts the head offices of the vast majority of the major Spanish companies, as well as the headquarters of three of the world's 100 largest companies (Telefónica, Repsol-YPF, Endesa).

While Madrid possesses a modern infrastructure, it has preserved the look and feel of many of its historic neighborhoods and streets. Its landmarks include the huge Royal Palace of Madrid; the Teatro Real (Royal theatre) with its restored 1850 Opera House; the Buen Retiro park, founded in 1631; the imposing 19th-century National Library building (founded in 1712) containing some of Spain's historical archives; an archaeological museum of international reputation; and three superb art museums: Prado Museum, which hosts one of the finest art collections in the world, the Museo Nacional Centro de Arte Reina Sofía, a museum of modern art, and the Thyssen-Bornemisza Museum, housed in the renovated Villahermosa Palace.

The population of the city is roughly 3.2 million (December 2005), while the estimated urban area population is 5.1 million. The entire population of the Madrid metropolitan area (urban area and suburbs) is calculated to be 5.84 million. The city spans a total of 607 km² (234 sq mi).

Names of the city and origin of the current name