It is well known that quantum systems can serve as extremely sensitive probes of gravity. A series of pioneering experiments, including with neutrons, atom interferometers and atomic clocks, have established a firm basis of quantum experiments that test effects of weak gravitational fields. The last few years have seen a renewed interest accompanied by a dramatic increase of experiments and experimental proposals to explore the interface between quantum physics and gravity. On the one hand, quantum optics and cold atom experiments have been pushing the sensitivity of measurements of space and time to unprecedented regimes. On the other hand, the fast progress in macroscopic quantum experiments may soon allow to study large quantum superposition states involving clocks or increasingly massive objects. The latter could open a completely new regime of experiments in which the source mass character of the quantum system starts to play a role. This is reminiscent of Feynman’s proposal at the 1957 Chapel Hill Conference on the generation of entanglement through gravitational interaction. I will provide a review of some of the milestone experiments, as well as the current status and challenges for entering the next generation of these experiments