The general aim is to present and clarify the notion of grounding, and promote its application to different debates in the philosophy of science. Along the way, I digress about a few specific questions regarding the metaphysics of grounding. As a result, my title ‘Grounding in the Philosophy of Science' is deceiving in at least two ways. First, it suggests a level of argumentative unity that is typical of monographs, when the present dissertation lumps together a series of almost independent arguments. Secondly, it implies a restriction of field to the philosophy of science, when much of the content extends far beyond these confines.