The Parc du Cinquantenaire or Jubelpark is a large public, urban park of 30 ha in the easternmost part of the European Quarter in Brussels, Belgium.
Most buildings of the U-shaped complex which dominate the park were commissioned by the Belgian government under the patronage of King Leopold II for the 1880 National Exhibition commemorating the fiftieth anniversary of the Belgian Revolution. During successive exhibitions in the same area, more structures were added. The centrepiece memorial arch, known as the Cinquantenaire Arch, was erected in 1905, replacing a previous temporary version of the arcade by Gédéon Bordiau. The structures were built in iron, glass and stone, symbolising Belgium's economic and industrial performance. The surrounding 30 ha park esplanade was full of picturesque gardens, ponds and waterfalls. It housed several trade fairs, exhibitions and festivals at the beginning of the century. In 1930, the government decided to reserve the Cinquantenaire for use as a leisure park.
The Royal Military Museum has been the sole tenant of the northern half of the complex since 1880.