What is the fastest recorded speed of a Greyhound (approximate)?

About 70 km/h (45 mph) is correct because Greyhounds are built for explosive sprinting: a deep chest with large heart and lungs, long legs, a flexible spine, and a double-suspension gallop let them cover ground with minimal air resistance. On tracks, their peak speeds cluster around this mark over short distances (roughly 200–400 meters). The other options help frame the range: 55–60 km/h (34–37 mph) is closer to the top speed of many athletic breeds, while 80 km/h (50 mph) pushes into cheetah territory and exceeds verified canine capability. Memory tip: G for Greyhound is the 7th letter of the alphabet—think “G = 7,” so roughly 70 km/h—and 45 mph pairs with a “45” lean in those tight racing turns.