A ramjet, sometimes referred to as a stovepipe jet, is a form of jet engine that contains no major moving parts and can be particularly useful in applications requiring a small and simple engine for high speed use; such as missiles. They have also been used successfully, though not efficiently, as tipjets on helicopter rotors.

Ramjets require considerable forward speed to operate well, and as a class work most efficiently at speeds around Mach 3, and this type of jet can operate up to speeds of at least Mach 5.

Ramjets employ a continuous combustion process, but are frequently confused with pulsejets, which use an intermittent combustion, but these are a quite distinct type.