The 14th Street–Union Square station is a New York City Subway station complex shared by the BMT Broadway Line, the BMT Canarsie Line and the IRT Lexington Avenue Line. It is located at the intersection of Fourth Avenue and 14th Street, underneath Union Square Park in Manhattan. The complex is near the border of several neighborhoods, including the East Village to the southeast, Greenwich Village to the south and southwest, Chelsea to the northwest, and both the Flatiron District and Gramercy Park to the north and northeast. The 14th Street–Union Square station is served by the 4, 6, L, N, and Q trains at all times; the 5 and R trains at all times except late nights; the W train on weekdays; and <6> train weekdays in the peak direction.

The BMT Broadway Line is a rapid transit line of the B Division of the New York City Subway in Manhattan. As of November 2016, it is served by four services, all colored yellow: the N and ​Q trains on the express tracks and the R and ​W trains on the local tracks during weekdays. The line is often referred to as the "N and R", since those were the only services on the line from 1988 to 2001, when the Manhattan Bridge's southern tracks were closed for rebuilding. The Broadway Line was built to give the Brooklyn Rapid Transit Company access to Midtown Manhattan.