National Rhododendron Garden, Botanical garden in Olinda, Victoria, Australia.

The National Rhododendron Garden is a botanical garden in Olinda, Victoria, that spreads across large grounds and houses tens of thousands of rhododendrons, azaleas, camellias, and spring bulbs. The garden combines these cultivated collections with native and exotic trees distributed across naturally sloping terrain.

The garden was established in 1960 by the Australian Rhododendron Society to collect and display rare varieties. A major bushfire in 1962 destroyed many of the original plantings, after which the garden was rebuilt.

The garden's former name, National Rhododendron Gardens, was dropped in 2017 when the site was renamed Dandenong Ranges Botanic Garden. The Australian Rhododendron Society, founded in Victoria in 1960, built the collection from cuttings taken from members' own gardens and from seeds sent by collections abroad, with further specimens gathered on trips to Nepal, India and New Guinea.

The site lies at almost 600 metres above sea level beside Dandenong Ranges National Park, with about 1,200 mm of rain a year and temperatures averaging five degrees cooler than Melbourne. Paths cross sloping ground, so wear sturdy shoes and carry rain protection. The ornamental lake, built in 1969, and Cherry Tree Grove, opened in 1995, are landmarks for orientation.

The Cherry Tree Grove was officially opened on 13 October 1995, when Prince and Princess Akishino of Japan planted a tree there. The grove blooms in September and early October, and the garden also holds a Japanese Garden among its smaller sections.