Fleay, David (1907-1993), an Australian zoologist, was the first person to breed a platypus (an unusual, egg-laying mammal) in captivity in 1944. He was considered one of the world's greatest authorities on the platypus. Fleay was also the first person to milk a taipan (Australia's largest venomous snake) to produce an antivenin (an antitoxin used to counteract snake venom) in 1950.

David Howells Fleay was born at Ballarat, in Victoria, Australia. He received his bachelor's degree from Melbourne University in 1931. While a student at the university, he shared a dormitory room with live owls for a time. He worked for the Education Department of Victoria from 1927 to 1934. From 1934 to 1937, he was a designer and curator for the Australian section of the Melbourne Zoo. He then became director of the Sir Colin MacKenzie sanctuary (now the Healesville Sanctuary) in Healesville, Victoria. At the sanctuary, Fleay and his staff studied rare and well-known Australian species, including the common wombat, wedge-tailed eagles, possum gliders, and tree kangaroos. In 1944, they celebrated the birth of the first platypus born in captivity.

In 1952, Fleay established a wildlife sanctuary in Burleigh Heads, Queensland. Working to conserve wildlife, he accepted any injured or sick animal or bird brought to him. His family became accustomed to sharing their house with orphaned animals and their bathtub with snakes. Fleay was the director of this sanctuary until the early 1980's, when he turned the facility over to the Queensland Parks and Wildlife Service. Today, the sanctuary (now named the David Fleay Wildlife Park) is a popular destination for tourists and school groups, as well as a research center. Many of the animals at the Wildlife Park are endangered or threatened.

For many years, Fleay wrote a nature column for a Brisbane newspaper, the Courier-Mail. He also wrote a number of books, including Living With Animals (1960). He cofounded the Wildlife Preservation Society of Queensland. The giant frog, Mixophyes fleayi, was named after him.