|Native name||Metro de Madrid|
|Number of lines||13|
|Number of stations||301|
|Annual ridership||626.4 million (2017)|
|Website||Metro de Madrid|
|Began operation||17 October 1919|
|Operator(s)||Metro de Madrid|
|Number of vehicles||2404[|
|System length||293.0 km (182.1 mi)|
1,435 mm (4 ft 8 1⁄2 in)
The Madrid Metro (
Some underground stations are large enough to hold public events, such as the three-day fitness festival in May 2011, which attracted 2,600 visitors. One station contains a 200-square-metre archaeological museum.
On 19 September 1916, a royal decree approved the 4 line plan for the creation of the metro of Madrid. The engineers who created the plan, Mendoza, González Echarte, and Otameni then began the process of raising the 8 million pesetas to begin the first phase of the project, the construction of Line 1 from Sol to Cuatro Caminos. Carlos Mendoza made contact with Enrique Ocharán, the director of Banco de Vizcaya, who offered 4 million pesetas on the condition that the public pledged an additional 4 million.
Mengemor published a brochure in order to persuade people to make donations. The men were able to raise 2.5 million pesetas of the 4 million they needed. King Alfonso XIII intervened and invested 1.45 million pesetas of his own money.
The first phase of construction was finished in 1919. It was constructed in a narrow section and the stations had 60 m platforms. The enlargement of this line and the construction of two others followed shortly after 1919. The Madrid metro was inaugurated on 19 October 1919, with King Alfonso cutting the ceremonial ribbon in the Cuatro Caminos station.
The king, the royal family, and others, then took part in the first official metro ride which went from Cuatro Caminos to Río Rosas, and took 40 seconds. There they stopped for one minute, before traveling to the Chamberí station which took 45 seconds. The trip went all the way to the end point, Sol. The king and his family then rode the metro back to Cuatro Caminos from Sol, this time without stopping. The journey took 7 minutes and 46 seconds.
After the journey, a lunch was served on the Cuatro Caminos platform, and the engineers were congratulated for creating a "miracle." 
Two days later, on 19 October 1919, the Madrid metro was opened to the public. On its first day, 390 trains ran, 56,220 passengers rode the metro, and the company earned 8,433 pesetas in ticket fares. .
During November and December 1919, the metro had an average of 43,537 passengers a day and earned an average of 6,530 pesetas a day in ticket sales. Due to their success, the company decided to expand more, and created 12,000 new shares to sell to the public in order to raise more funds to fund further expansion. .
The Company then began to gather materials necessary to expand the Line 1 from Sol-Progreso-Antón Martín-Atocha.
On 31 July 1920 the company submitted it proposal to extend Line 1 from Atocha to Puente de Vallecas. In 1921 the company declared its interest in beginning the line from Sol-Ventas, with the first phase of the project being built from Sol-Goya, along Calle Alcalá.
Work began on 27 March 1921 to expand the Line 1 from Atocha to Vallecas, and to begin construction on a line from Sol-Goya.
On 26 December 1921 the Sol-Atocha section of the Line 1 was inaugurated, adding three new metro stops to the line: Progreso, Antón Martín, and Atocha. The king and queen, Don Alfonso, and Doña Victoria attended the inauguration. .
In 1924, traffic in Madrid switched from driving on the left, to driving on the right, but the lines of the Madrid Metro kept operating on the left hand side. In 1936, the network had three lines and a branch line between Opera and Norte railway station. All these stations served as air raid shelters during the
In the 1960s, a suburban railway was constructed between Plaza de España and Carabanchel, linked to lines 2 (at Noviciado station with a long transfer) and 3. A fifth metro line was constructed as well with narrow section but 90 m platforms. Shortly after opening the first section of line 5, the platforms in line 1 were enlarged from 60 to 90 m, closing Chamberí station since it was too close to Iglesia (less than 500 m). Chamberí has been closed ever since and has recently been opened as a museum.
In the early 1970s, the network was greatly expanded to cope with the influx of population and
At the beginning of the 1990s, control of the network was transferred to a public enterprise, Metro de Madrid. More large-scale expansion projects were carried out. Lines 1, 4 and 7 were extended and a new line 11 was constructed towards the outlying areas of Madrid. Lines 8 and 10 were joined together into a longer line 10 and a new line 8 was constructed to expand the underground network towards the airport. The enlarged line 9 was the first to leave the outskirts of Madrid to arrive in Rivas-Vaciamadrid and Arganda del Rey, two towns located in the southeast suburbs of Madrid.
In the early 2000s, a huge project installed approximately 50 km (31 mi) of new metro
MetroSur, one of the largest ever
Most of the efforts of
There are numerous expansion and improvement projects pending; many suspended due to the financial crisis since 2009. For example, lines 1 and 5 reaching