The zoo started as Bellevue Pleasure Gardens, a public park and recreational area, in 1911 on the slopes of Cavehill. The gardens were opened by Belfast City Tramways as an inducement to Belfast's residents to use the company's new tramway. 12 acres of the site were redeveloped as a zoo in 1933. Initially the zoo was very popular, attracting over 280,000 visitors a year. During World War II many of the zoo's dangerous animals were put down. The decline continued into the 1960s, when the zoo's facilities fell into disrepair. Belfast City Council acquired the facility in 1962, starting a long process of renovation. Under the supervision of manager John Stronge, the new zoo eventually opened in 1978.

The zoo houses many more than 1,200 animals of 160 species including Asian Elephants, Barbary lions, a White tiger (one of the few in the United Kingdom), three species of penguin, a family of Western Lowland Gorillas, a troop of Common Chimpanzees, a Red Panda and several species of Langur.