The Royal Greenhouses of Laeken (French: Serres Royales de Laeken, Dutch: Koninklijke Serres van Laken) are a vast complex of monumental heated greenhouses in the park of the Royal Castle of Laeken in the north of Brussels. The historic complex contains tropical, sub tropical and cold greenhouses. The greenhouses are part of the Royal Park, and the royal private gardens and usually not open for visitors.

Famous is the royal botanic collection, with old plants from Africa and various species of flowers which are cultivated inside the royal greenhouses for use at court. Though the current collection has lost many cultivars since the death of King Leopold II, the collection is still famous. In 1909, there were 314 species of camellias in the royal collection, with more than 1000 plants. Today, only 305 remain. The camellias are the world’s largest and oldest collection in a greenhouse. The Orange tree collection of Leopold II was renowned with 130 trees aged 200 to 300 years; one even 400 years. In the 1970s, only 45 trees were still alive.

The royal complex can only be visited each year during a two-week period in April–May, when most flowers are in full bloom. Other times, the greenhouses are visited by heads of state during official visits.