Tuen Mun District is one of the 18 administrative districts of Hong Kong. It is the westernmost continental district of Hong Kong. It had a population of 487,546 in 2011. Part of the district is the Tuen Mun New Town, which contains one of the largest residential areas in the New Territories.

Tuen Mun New Town, commonly referred to simply as Tuen Mun, is a satellite town of Hong Kong. It is one of the new towns that were developed by the Hong Kong Government in the New Territories from the 1960s. It was built around the existing rural local centre of Tuen Mun. The new town covers most of the urban area of Tuen Mun District.