The Kowloon Southern Link is a section of the MTR West Rail Line, linking Nam Cheong Station and East Tsim Sha Tsui Station. The rail link is fully underground, lies along the south-west coastline of Kowloon Peninsula, east of rail tracks of the Tung Chung Line and Airport Express. Kowloon Southern Link has one underground intermediate station called Austin Station (formerly West Kowloon Station). It is located adjacent to the Canton Road Government Offices, close to Kowloon Station of Tung Chung Line and Airport Express. However, the structures do not provide a direct transfer between the two stations.
The project was originally proposed and carried out by Kowloon-Canton Railway Corporation (KCRC) to link the KCR West Rail that terminated at Nam Cheong Station to the KCR East Rail at Hung Hom Station. The tracks between Hung Hom and East Tsim Sha Tsui Station had opened in 2004, to alleviate surface traffic jams and congestion at Kowloon Tong Station caused by passengers transferring between the KCR East Rail and the MTR.
The initial plans included an additional intermediate station: Canton Road Station, to serve the adjacent shopping centres. The station was eventually omitted from the project due to failed negotiations between the rail operator and property developers, the outcome being officially announced on 6 December 2004.
Construction of the Kowloon Southern Link began in late 2005 by the KCRC, after the company's network was taken over by MTR Corporation (MTRC) on 2 December 2007, the project was continued by MTRC. The link went into service on 16 August 2009.
Upon the completion of the rail link, the West Rail Line assumed the tracks from the East Tsim Sha Tsui to Hung Hom portion of the East Rail Line. At the same time both the East Rail and West Rail Lines were altered to terminate at Hung Hom Station, with the platform and tracks at Hung Hom being rearranged to provide cross-platform interchange between the two lines (it will form two sets of island platforms).
Upon the opening of the extension, a new Tuen Mun-Hung Hom Monthly Pass was introduced for unlimited rides of the whole West Rail line (including the new extension). Its current price is $530.