Located at the intersection of 145th Street and Lenox Avenue in Harlem, Manhattan, it is served by the 3 train at all times.

Built for the Interborough Rapid Transit Company (IRT), the 145th Street station contains two side platforms that can only fit six and a half train cars, unlike almost all other IRT stations, which are able to fit full-length ten-car trains.

The station was added to the National Register of Historic Places in 2005, and was closed from July to November 2018 for extensive renovations.

The platforms contain exits to Lenox Avenue's intersection with 145th Street and are not connected to each other within fare control.

[5]: 21  However, development of what would become the city's first subway line did not start until 1894, when the New York State Legislature passed the Rapid Transit Act.

It called for a subway line from New York City Hall in lower Manhattan to the Upper West Side, where two branches would lead north into the Bronx.

[5]: 148  The Rapid Transit Construction Company, organized by John B. McDonald and funded by August Belmont Jr., signed the initial Contract 1 with the Rapid Transit Commission in February 1900,[7] in which it would construct the subway and maintain a 50-year operating lease from the opening of the line.

[6]: 4  Belmont incorporated the Interborough Rapid Transit Company (IRT) in April 1902 to operate the subway.

[5]: 182 The 145th Street station was constructed as part of the IRT's East Side Branch (now the Lenox Avenue Line).

[19] The New York City Transit Authority (NYCTA) announced plans in 1956 to add fluorescent lights above the edges of the station's platforms.

This was done to correct a major water problem that had existed for many years due to the presence of the Harlem Creek and other underground streams, which caused extensive flooding, water damage, and seepage problems that occasionally contributed to severe service disruptions.

Supplemental shuttle bus service connecting to other lines in the area were provided for much of this time.

The lowest sections of the trough's outer walls are composed of transverse arches 5 feet (1.5 m) wide.

[4]: 5  Each platform consists of 3-inch-thick (7.6 cm) concrete slabs, beneath which are located drainage basins.

Columns between the tracks, placed atop the transverse arches, support the jack-arched concrete station roofs.

The ceiling is about 15 feet (4.6 m) above platform level; the section of the ceiling north of the fare control area is smooth, and the section south of fare control is composed of segmental vaults supported by the center columns.

[55] Approximately 200 feet (61 m) north of the station is a diamond crossover for the approach to the northern terminal of the 3 train at Harlem–148th Street.

Approximately 300 feet (91 m) south of the station is the 142nd Street Junction with the IRT White Plains Road Line.

[58] The street staircases were replaced with relatively simple, modern steel railings like those seen at most New York City Subway stations.