Subsidiary entrances are located in Exhibition Road giving access by pedestrian tunnel to the Natural History, Science and Victoria and Albert Museums.

The deep-level platforms have remained largely unaltered, although the installation of escalators in the 1970s to replace lifts improved interchanges between the two parts of the station.

[7] The original South Kensington station, designed by the MR's engineer John Fowler,[8] had two platforms although it was intended that this would be supplemented as DR services extended.

The subway was originally intended to go as far as the Royal Albert Hall, but the construction of the Imperial Institute meant the tunnel emerged at the Science Museum where it exits onto Exhibition Road.

Although it had cost £42,614 to construct (approximately £5.81 million today),[12] it was closed on 10 November 1886 and afterwards was opened only occasionally for special museum events.

[17] In 1907, the station reopened to designs by George Campbell Sherrin, including a new art deco entrance with an arcade and a new ticket hall, with canopies added to the platforms replacing the two trainsheds erected in 1868 and 1871.

The arcaded station entrance and shops, the brick retaining walls to the sub-surface platforms and the Exhibition Road pedestrian tunnel are Grade II listed structures.

[22][23] Over the decades, there were also a number of aborted attempts to build above the station with hotels, offices and a shopping mall proposed at times.

The southern section of the Inner Circle was suffering considerable congestion between South Kensington and Mansion House, between which stations the DR was running an average of 20 trains per hour with more in the peak periods.

[24] To relieve the congestion, the DR planned an express deep-level tube line starting from a connection to its sub-surface tracks west of Gloucester Road and running to Mansion House.

The tunnels were planned to run about 60 to 70 feet (18–21 m) beneath the existing sub-surface route with only one intermediate stop at Charing Cross (now Embankment).

[29] A new surface building on Pelham Street for the lifts was designed by Leslie Green with the GNP&BR's distinctive ox-blood red glazed terracotta façade.

[30] The unused westbound tunnel was used during World War I to store art from the Victoria & Albert Museum and china from Buckingham Palace and, from 1927 to 1939, was used as a signalling school.

During World War II it contained equipment to detect bombs falling in the River Thames which might require the emergency floodgates on the under-river tunnels to be closed.

[37] The proposal includes bringing the disused northern platform back into use for eastbound trains, a new entrance to Thurloe Street, a reconfigured ticket hall and provision of step-free access throughout the station.

[45] South Kensington is one of two tube stations (the other being Sloane Square) mentioned in the song "When you're lying awake" from the operetta Iolanthe by Gilbert and Sullivan.