The Vympel R-37 is a Russian hypersonic air-to-air missile with very long range. The missile and its variants also had the names K-37, izdeliye 610 and RVV-BD, and the NATO codenames "Axehead" and "Andi". It was developed from the R-33.

A hypersonic weapon is a weapon capable of travelling at hypersonic speed, defined as between 5 and 25 times the speed of sound or about 1 to 5 miles per second.