The zoo was built at a cost of $9 million granted by the government of Singapore and opened on 27 June 1973. It is operated by Wildlife Reserves Singapore, who also manage the neighbouring Night Safari, River Safari and the Jurong Bird Park. There are about 315 species of animal in the zoo, of which some 16 percent are considered to be threatened species. The zoo attracts 1.7 million visitors each year.
From the beginning, Singapore Zoo followed the modern trend of displaying animals in naturalistic, 'open' exhibits with hidden barriers, moats, and glass between the animals and visitors. It houses the largest captive colony of orangutans in the world.