 Even a casual reader of Kant’s Critique of Pure Reason (Kritik der reinen Vernunft, first published in 1781) will notice the prominence he gives to his discussion of space and time. In tandem, scholars consider this discussion to be central to Kant’s so-called critical philosophy. Given Kant’s reputation for developing difficult, not to say obscure, philosophical views, it will also not surprise the reader to learn that there is no consensus on how Kant’s conception of space and time ought to be characterized and explicated. So the goal of this entry is to bring some clarity to Kant’s views by situating them historically and philosophically within the milieu of some central debates concerning space and time in the early modern period, especially the rich century between the first edition of Newton’s Principia mathematica, which was first published in 1687, and the publication of the second edition of the Critique of Pure Reason exactly a hundred years later. The difficulty of comprehending Kant’s views gives interpreters a reason to place a special emphasis on context—I will especially highlight Kant’s reactions to his most significant predecessors in this area, Leibniz and Newton. The focus throughout will be on Kant’s magnum opus, the Critique of Pure Reason. Following tradition, and to some extent Kant’s own lead, the focus will also be on space and on our representation of space, although parallel points concerning time (and its representation) will sometimes be indicated.