The Zoological Society of London (ZSL) is a charity devoted to the worldwide conservation of animals and their habitats. It was founded in 1826. Since 1828, it has maintained London Zoo, and since 1931 Whipsnade Zoo.

London Zoo, previously known as ZSL London Zoo or London Zoological Gardens and sometimes called Regent's Park Zoo, is the world's oldest scientific zoo. It was opened in London on 27 April 1828, and was originally intended to be used as a collection for scientific study. In 1831 or 1832, the animals of the Tower of London menagerie were transferred to the zoo's collection. It was opened to the public in 1847. As of December 2022, it houses a collection of 14,926 individuals, making it one of the largest collections in the United Kingdom.