| Line 10 | |
| Native Name: | Línea 10 |
| Native Name Lang: | es |
| Image Alt: | Begoña station, located beneath the Cuatro Torres Business Area (CTBA) |
| Type: | Rapid transit |
| System: | Madrid Metro |
| Locale: | Madrid |
| Stations: | 31 |
| Owner: | CRTM |
| Operator: | CRTM |
| Character: | Underground |
| Stock: | AnsaldoBreda 7000, 9000 |
| Linelength Km: | 36.514 |
| Map State: | collapsed |
Line 10 of the Madrid Metro is a rapid transit line in Madrid that is actually the product of two formerly separate lines. Today the route begins at (San Sebastián de los Reyes) and ends at (Alcorcón). Passengers must transfer at between the "line 10A" segment, which covers the portion of the route south of the station, and "line 10B," which extends north to Hospital Infanta Sofía.
Line 10 provides access to the Cuatro Torres Business Area at station, the AZCA at, as well as the Chamartín Railway station, Plaza de Castilla, Plaza de España, Principe Pío and Casa de Campo. The line links the towns of Alcobendas and San Sebastián de los Reyes with Madrid.
The line is the product of two lines, the former Line 8 from to Nuevos Ministerios and the former Suburbano (also known as Line S) from to, this section being named line 10 in the 1980s, and formerly operated by FEVE until the management of Line S was transferred to the Community of Madrid. In the 1990s, Madrid planned for these two lines to become one, but there was a problem in that Line 8 used wider train sets than Line S. As a remedy, Madrid decided to rebuild the Suburbano section to fit the large-profile rolling stock, a project that took five years to complete. This project removed all island platforms, widened tunnels, and modernized stations. The section between Alonso Martinez and Nuevos Ministerios was completely built, with an intermediate station at . While this project was in progress the line was extended from the new Casa de Campo station to . The former section between Casa de Campo and Aluche was transferred to Line 5, which now terminates at Casa de Campo.
On 11 April 2003, Line 10 was extended to where it meets Line 12 (also known as Metro-Sur). The last two stations on this extension are in fact outside Madrid and in the town of Alcorcón. is also unique to this line and it is one of the few stations to have an island platform instead of side platforms. On 22 December 2006, was opened as an infill station between and . This station was opened to serve the nearby Aircraft Museum and is named after it. On 26 April 2007, the line was extended north from Fuencarral to Hospital del Norte (Hospital Infanta Sofía as of August 2008).
The station after Fuencarral, is a transfer station between the regular line ("line 10A") and the northern extension ("line 10B"), the segment from Tres Olivos to Hospital Infanta Sofía.
Proposed plans for Line 10 include the building of a new station between Colonia Jardín and Aviación Española called . Also there are plans to extend the line from Puerta del Sur to and further onto the new Xanadu Shopping Centre. However this is unlikely because Metro Sur already reaches Mostoles from Puerta Del Sur, but via .
Line 10A uses 6-car trains of class 7000, and line 10B uses 3 car trains of class 9000.
Some Line 10 units are sometimes used for Line 7 service.