Largest zoo (by species)
Moscow Zoo
1226 total number
Russian Federation (Moscow)

Currently the world's largest zoo in terms of number of species in residence is Moscow Zoo (Moskovsky Zoo-park) in Russia. The 21.4-hectare (53-acre) site, which includes numerous bespoke enclosures and open paddocks, an aquarium and an aviary, houses more than 24,500 individual animals representing 1,226 different species, as of 1 November 2020. Residents include numerous record-breaking species including giraffes (tallest animal), Chinese alligators (smallest crocodilian), moose (largest deer), reticulated python (longest snake), the peregrine falcon (fastest bird in a dive) and the African giant millipede (most legs on an animal).

Moscow Zoo was established in 1864 by a public society led by three biology professors from the nearby Moscow University; during its first year, the zoo housed 134 domestic animals and 160 wild animals. The zoo was nationalized in 1919 and has been under government ownership since 1922.

Since the mid-1990s, Moscow Zoo has also overseen a 200-ha (495-acre) conservation centre in the countryside outside of the capital, near Volokolamsk City, which focuses on breeding rare and endangered species.