The New York City Subway is a rapid transit system owned by the City of New York and leased to the New York City Transit Authority, a subsidiary agency of the Metropolitan Transportation Authority and also known as MTA New York City Transit. It is one of the oldest and most extensive public transportation systems in the world, with 468 stations in operation (421 if stations connected by transfers are counted as a single station); 229 miles (369 km) of routes, translating into 656 miles (1,056 km) of revenue track; and a total of 842 miles (1,355 km) including non-revenue trackage. In 2008, the subway delivered over 1.623 billion rides, averaging over five million on weekdays, 2.9 million on Saturdays, and 2.3 million on Sundays.

The New York City Subway trails only the metro systems of Tokyo, Moscow and Seoul in annual ridership and carries more passengers than all other rail mass transit systems in the United States combined. Among the world's busiest metro systems it is the only one to run 24 hours a day, 365 days a year.