Line 10 of the Beijing Subway is the second loop line in Beijing's rapid transit network as well as the second longest and most widely used line. The line is 57.024 km (35.433 mi) in length, and runs entirely underground through Haidian, Chaoyang and Fengtai Districts, either directly underneath or just beyond the 3rd Ring Road. The Line 10 loop is situated between 2 and 6 kilometres outside the Line 2 loop, which circumnavigates Beijing's old Inner City. Every subway line through the city centre intersects with Line 10, which has 24 transfer stations along route, and 45 stations in all. Line 10's color is capri.

Rapid transit or mass rapid transit (MRT), also known as metro, is a type of high-capacity public transport that is generally built in urban areas. A rapid transit system that primarily or traditionally runs below the surface may be called a subway, tube, or underground. Unlike buses or trams, rapid transit systems are railways, usually electric, that operate on an exclusive right-of-way, which cannot be accessed by pedestrians or other vehicles. They are often grade-separated in tunnels or on elevated railways.