Katoomba is the chief town of the City of Blue Mountains in New South Wales, Australia and the administrative headquarters of Blue Mountains City Council. Ka-toom-ba is an Aboriginal term for "shining falling water" and takes its name from a waterfall that drops into the Jamison Valley. The name Katoomba was adopted in 1877 and the town achieved municipality status in 1889.

Katoomba's main industry is tourism based on scenic mountain scenery. The rock formation known as the Three Sisters, viewable from Echo Point about two kilometres south of the main town, is the most famous feature. A short walk from Echo Point leads to The Giant Stairway which provides access to a number of nature walks through the Valley. Some of these are quite rugged and not recommended for inexperienced walkers. The local geography includes extensive areas of dense sub-tropical rainforest, hanging swamps and a series of waterfalls with a relatively low water volume.

Other attractions include Scenic World, a tourist complex in the southwest of the town. This site is home to the steepest funicular railway in the world, the Katoomba Scenic Railway, which was originally built to facilitate coal and oil shale mining in the Jamison Valley. Scenic World also offers the Scenic Skyway cable car, which travels over an arm of the Jamison Valley and offers views of Katoomba Falls and Orphan Rock.

Katoomba is well-served by hotels and guest-houses, the oldest and most prominent of which is the Carrington Hotel, established in 1882 and occupying the highest point in town. The nearby village of Leura also features numerous well-appointed hotels and health spas and Medlow Bath boasts the Grand Hydro Majestic Hotel, originally built in 1891. The busy town centre, centered on Katoomba Street, features dozens of cafes and restaurants, including the Paragon which dates the early 1900s, as well as a number of second-hand book and antique stores.

Katoomba and nearby Medlow Bath were first developed as tourist destinations towards the end of the 19th century. Coal and shale mining was also carried out in the Jamison Valley for many years, but the seams were completely exhausted by the early 20th century and Katoomba was established as a resort town. By the 1960s, Katoomba had somewhat declined, and several of its guest houses were converted for other purposes including convalescent hospitals. Housing was inexpensive, allowing many young families to establish themselves, many of whom still live there. In the 1980s, the guest houses and hotels again became fashionable and many were restored to their former glories.

The scenic beauty and tranquillity of Katoomba and the surrounding Blue Mountains area have long made Katoomba a haven for Sydney-siders looking for rest and relaxation.
"In distance I found strength. Katoomba gave me peace of mind."