The Baku suburban railway or Absheron Circular line is a 91 km (57 mi) commuter rail service which began in 2019, serving the Azerbaijani capital Baku.

Baku Metro is a rapid transit system serving Baku, the capital of Azerbaijan. First opened on 6 November 1967 when Azerbaijan was part of the Soviet Union, its features are typical of former Soviet systems, including very deep central stations and exquisite decorations that blend traditional Azerbaijani national motifs with Soviet ideology. At present, the system has 40.7 kilometres (25.3 mi) of bidirectional tracks, made up of three lines served by 27 stations. The metro is the only in Azerbaijan, the fifth in the Soviet Union and the thirty-fourth in the world. In 2015, it carried 222.0 million, passengers, an average daily ridership of approximately 608,200. In 2019, it carried 229.7 million, an average daily ridership of 629,315.