John Bushnell "Jack" Hanna is an American zookeeper who is the Director Emeritus of the Columbus Zoo and Aquarium. He was Director of the zoo from 1978 to 1993, and is viewed as largely responsible for elevating its quality and reputation. His media appearances have made him one of the most notable animal experts in the United States.

Jack Hanna is a media savvy zoologist who makes frequent appearances on television talk shows and hosts his own syndicated series, Jack Hanna's Animal Adventures. Hanna got his start in the zoo business in Florida, but made his name as the director of Ohio's Columbus Zoo, a post he held from 1978 to 1992. Hanna turned the rundown zoo into a nationally recognized attraction, in part through appearances on the TV shows of David Letterman and Larry King. After leaving his post as director, he was named Director Emeritus and embarked on a television career. His series, which explores animal stories all over the world, has been on the air since 1997. Hanna has also published several books, including the autobiographical Monkeys on the Interstate (1988) and the children's book Let's Go to the Petting Zoo with Jungle Jack (1991).

Hanna has been accused by animal rights organizations of exploiting animals to advance his career... In 1995 a baby cougar, brought by Hanna to a public appearance, bit politician Newt Gingrich on the chin.

Hanna published his autobiography, Monkeys on the Interstate in 1989. He has published many books for children as well. He has been the host of the syndicated television show "Jack Hanna's Animal Adventures" since 1993. Hanna also occasionally contributes commentary as an animal expert on various local and national news programs, and has done guest spots on other shows such as Larry King Live, Nancy Grace, Maury, and Hollywood Squares. He was also named one of the "50 Most Beautiful People" by People magazine in 1996