The notions of essence and metaphysical grounding have belonged to the metaphysicians’ conceptual toolkit at least ever since Aristotle, and are indeed of central importance to metaphysics. Until quite recently, analytic philosophers were happy with modal accounts of these notions - roughly, with the view that essence is nothing but de re necessity, and that metaphysical grounding is necessary (or “strict”) implication. Over the past fifteen years or so, an increasing number of philosophers have become convinced that the traditional purely modal accounts of essence is inadequate, and indeed that the notion is either primitive or analysable in completely different terms - and something similar happened over the past ten years regarding the notion of metaphysical grounding. Given the importance of these notions to metaphysics, a number of studies have accordingly come out, whose aim is to clarify or analyse them outside of the modal paradigm. I have personally largely contributed to both fields of study, in particular through my current SNF professeur boursier project “The Theory of Essence”, and my book Existential Dependence and Cognate Notions. Strangely enough, the overwhelming majority of these studies concern essence or metaphysical grounding but not both. Yet, as very few philosophers have recently noticed, there appears to be deep and important connections between the concept of essence and that of metaphysical grounding. These apparent connections are at least four: (1) As it has been suggested, it seems that for some if not all statements of metaphysical ground which hold, their holding reflects the nature of certain entities. (2) As it has also been suggested, it is prima facie plausible to claim that the concept of ground is analysable in terms of the concept of essence. (3) One way of formulating essentialist claims involves the explanatory locution “in virtue of”: in order to say that a given proposition is essential to an entity, we can say that the proposition holds in virtue of the nature of that entity. It is natural in such contexts to think of the explanatory locution as expressing (the converse of) metaphysical grounding. (4) It is natural to understand the propositions which are essential to an entity as providing an explanation of the nature of that entity, i.e. of what the entity is. These explanations, if such there be, must be “metaphysical” (as opposed to e.g. causal or merely conceptual), and it is prima facie plausible to hold that they just consist in links of metaphysical grounding. I started to think of such connections between the concept of essence and that of metaphysical grounding while working on my PhD thesis, which then became my book Existential Dependence and Cognate Notions, and since the beginning of my current professeur boursier project on essence I became more and more convinced that there are such connections - in particular that either one of the two notions should be definable in terms of the other, or that both should be analysable in terms of a further notion. The primary aim of this research project is twofold: (i) to get clear about which connections hold between essence and metaphysical grounding, and to account for such connections, and (ii) to further the clarificatory work on each of the two concepts which has been carried out over the past few years, in particular by myself. The initial hope is that it is going to be possible to analyse one in terms of the other, perhaps along lines similar to what is suggested in (2) above, or to analyse the two concepts in terms of a third, more fundamental notion. I want then to study the consequences of the results obtained on some “applied” issues, i.e. of issues where the concept of essence and grounding are involved as tools used in order to achieve certain goals, e.g. to define or analyse other key metaphysical notions (like e.g. substance, dependence, supervenience), or to characterise certain debates (like e.g. the idealism / realism distinction or the debate between monists and pluralists). The project thus nicely prolongs my current professeur boursier project on the theory of essence and my past work on metaphysical grounding.