The Blue Mountains Botanic Garden, originally known as the Mount Tomah Botanical Garden, is a 28-hectare (69-acre) public botanic garden located approximately 100 kilometres (62 mi) west of the Sydney central business district at Mount Tomah in the Blue Mountains, in New South Wales, Australia. The garden is heritage-listed and is located on the boundary of the UNESCO World Heritage Site Greater Blue Mountains Area and can be accessed via the Bells Line of Road.

The garden was established in 1972. It includes an additional 128 hectares (320 acres) of land dedicated to conservation. The garden is 1,000 metres (3,300 ft) AHD, and it specializes in cool-climate plants that would not grow well in Sydney's warmer conditions. The gardens are managed by the Botanic Gardens Trust trading the Botanic Gardens and Centennial Parklands, that also has responsibility for the Royal Botanic Gardens, Sydney and the Australian Botanic Garden at Mount Annan. The Trust is a division of the Department of Environment and Planning.

The land was originally granted to Susannah Bowen, the mother of George M. C. Bowen, in 1830. She had arrived in the colony in 1828.

• Australian Botanic Garden Mount Annan
• Auburn Botanical Gardens
• Macquarie Culvert
• National Herbarium of New South Wales
• Royal Botanic Garden, Sydney
• The Domain, Sydney

• Official website Blue Mountains Botanic Garden