The rolling stock of the Washington Metro system consists of 1,242 75-foot (22.86 m) cars that were acquired across seven orders. All cars operate as married pairs, with systems shared across the pair. The 7000-series cars, the system's newest, have an operator's cab in only one of each married pair's cars and operate in groups of three or four.

The Washington Metro, often abbreviated as the Metro and formally the Metrorail, is a rapid transit system serving the Washington metropolitan area of the United States. It is administered by the Washington Metropolitan Area Transit Authority (WMATA), which also operates the Metrobus service under the Metro name. Opened in 1976, the network now includes six lines, 98 stations, and 129 miles (208 km) of route.