The Meise Botanic Garden (Dutch: Plantentuin Meise, French: Jardin botanique de Meise; until 2014 called the National Botanic Garden of Belgium (Dutch: Nationale Plantentuin van België, French: Jardin Botanique National de Belgique)) is located in the grounds of Bouchout Castle in the town of Meise, just north of Brussels in the province of Flemish Brabant. It is one of the largest botanical gardens in the world with an extensive collection of living plants in addition to a herbarium of over 3 million specimens. The current garden was established in 1958 after it moved from the centre of Brussels; the former site is now the Botanical Garden of Brussels. Researchers at the garden conduct research particularly on Belgian and African plants.

The Botanic Garden contains about 18,000 plant species—about 6% of all known plant species of the world. Half are in greenhouses, the other half, including cultivated and indigenous plants, are outdoors. The gardens are grouped around the castle and lake of the Bouchout domain. The mission statement of the Meise Botanic Garden specifies the increasing and spreading “the knowledge of plants” and contributions to “the conservation of biodiversity.”