Colo was a western gorilla widely known as the first gorilla to be born in captivity anywhere in the world and the oldest known gorilla in the world in 2017. Colo was born at the Columbus Zoo and Aquarium to Millie Christina (mother) and Baron Macombo (father), and lived there for her entire life. She was briefly called "Cuddles" before a contest was held to officially name her. Colo's name was derived from the place of her birth, Columbus, Ohio.

The western gorilla is a great ape found in Africa, one of two species of the hominid genus Gorilla. Large and robust with males weighing around 168 kilograms (370 lb), the species is found in a region of midwest Africa, geographically isolated from the eastern gorilla. The hair of the western species is significantly lighter in color.