The Airport express in Hong Kong is an extension of the MRT (Mass Rapid Transit) system that is the most commonly used public transportation system in Hong Kong. The Airport Express line continues to Hong Kong Station in the Central and Western District, crossing under the harbor to West Kowloon, where it connects to Kowloon Station. The line then runs along the western side of the Kowloon peninsula, and crosses over a bridge to Tsing Yi Island where it connects with Tsing Yi Station. From here the line crosses the major Tsing Ma Bridge before running parallel to the north Shore of Lantau Island and up to the 機場快線 and ending at the adjacent AsiaWorld-Expo Station.

The Airport express is specifically designed to be used by passengers commuting to and from the Airport and thus is much more comfortable than the average MRT in Hong Kong. For example a baggage hold can be found near every seat where passengers can store there bags safely without much hassle. A large LCD screen television can be found at the front of each compartment of the train and passengers can listen to the television broadcast through speakers fitted in each seat. All in all, the Airport express is more spacious and passenger friendly, in fact it is as if the in flight cabin experience has been brought in to the train!

Airport Express passengers can check in for their flights and collect their boarding passes at the Hong Kong and Kowloon stations at no extra cost. A free airport shuttle bus service is conducted from the Hong Kong and Kowloon stations to major hotels on Hong Kong Island, Yau Tsim Mong District, and also from Hung Hom Station.