18th Street was a station on the Chicago Transit Authority's South Side main line, which is now part of the Green Line.

The station was located at 18th Street and Wabash Avenue in the Near South Side neighborhood of Chicago.

[2] The South Side Elevated Railroad, the first rapid transit company in Chicago, opened on June 6, 1892, with ten stations, one of which was located on 18th Street.

[a][3] In 1907, the railroad was allowed by the city to construct a third track for express operations.

In exchange, it promised to demolish the station houses north of 43rd Street, including all of the original street-level station houses, and replace them with mezzanines in order to clear the alleyway below the track.