The fastest properly authenticated cheetah was a female South African cheetah (Acinonyx jubatus jubatus) named Sarah that lived in the Cincinnati Zoo. She was known as the world’s fastest land mammal according to National Geographic magazine. She ran 100 meters in 5.95 seconds in 2012 when she was 11 years old, and was radar-timed at up to 61 miles (98.1 kilometers) an hour. She died (put to sleep because of her diminished quality of life) on 22 January 2016 at the age of 15. Photo: a captured image of Sarah from a high speed video clip.