The Boeing 367-80, known simply as the Dash 80, is an American quadjet prototype aircraft built by Boeing to demonstrate the advantages of jet propulsion for commercial aviation. It served as basis for the design of the KC-135 tanker and the 707 airliner.

The Dash 80 first flew in 1954, less than two years from project launch. Its US$16 million cost (equivalent to $154 million today) was an enormous risk for Boeing, which at the time had no committed customers. Only one example was built, which has been preserved and is currently on public display at the Smithsonian’s National Air and Space Museum’s Udvar-Hazy Center in Virginia.