A Scintillometer is a scientific device used to measure atmospheric optical disturbances called scintillations, which are caused by fluctuations of the refractive index of air.[1] The air's refractive index is influenced by temperature, humidity, and pressure. The device thus allows measurements of the transfer of heat between the Earth's surface and the air above it called the "sensible heat flux"[2].

The term Scintillometer has been used, in its original sense (though relatively infrequently today) to refer to a Scintillation counter, which measures ionizing radiation.