The City of Blue Mountains is a local government area of New South Wales, Australia, governed by the Blue Mountains City Council. The city is located in the Blue Mountains, on the Great Dividing Range at the far western fringe of the Greater Sydney area.

The mayor of Blue Mountains City Council is Councillor Mark Greenhill, a member of the Labor Party.

The urban part of the city consists of a ribbon of close or contiguous towns which lie on the Main Western railway line, served by NSW TrainLink's Blue Mountains Line, and Great Western Highway between Emu Plains and Lithgow. About 70% of the city's area is within the Blue Mountains National Park which lies north and south of the ribbon of towns. The National Park is part of the much larger Greater Blue Mountains Area World Heritage Site and the city brands itself as "The City Within a World Heritage National Park". The towns and villages are generally grouped into lower, mid, and upper mountains. The economy of the upper mountains is dependent almost entirely on tourism ^{[citation needed]}. The road to Sydney, the Great Western Highway, is mostly dual carriageway but is relatively slow due to the urban development and hilly terrain. The electric train service integrates into Sydney Trains, Sydney's suburban rail network.

The main towns and villages in the City of Blue Mountains are:

The City of Blue Mountains has a number of heritage-listed sites, including the following sites listed on the New South Wales State Heritage Register:

The City of Blue Mountains has sister city relationships with the following cities:^[67]

• Sanda, Hyōgo, Japan
• Flagstaff, Arizona, US

• List of local government areas in New South Wales