Satellite Laser Ranging (SLR) is a space geodetic technique that consists in the measurement of the time-of-flight of laser photons emitted from ground stations to retroreflectors onboard satellites in orbit. Accurate and precise observations, at the level of a few millimetres, of the instantaneous ranges to the targets tracked are thus acquired, enabling a host of applications that include, among others, precise orbit determination and orbit validation, experiments in fundamental physics, time transfer, lunar physics, the determination of the Earth’s gravity field, space debris tracking, and contributing to the realization of a global terrestrial reference frame. Evolving on the back of progress in fields such as laser and photodetection technology, SLR has seen remarkable improvements since its inception in the 1960s, becoming the mature space geodetic technique that it is today.