Are space and time fundamental features of our world or might they emerge from something else? The Foundation of Reality brings together metaphysicians and philosophers of physics working on space, time, and fundamentality to address this timely question. Recent developments in the interpretation of quantum mechanics and the understanding of certain approaches to quantum gravity have led philosophers of physics to propose that space and time might beemergent rather than fundamental. But such discussions are often conducted without engagement with those working on fundamentality and related issues in contemporary metaphysics. This book aims to correct this oversight. The diverse contributions to this volume address topics including the nature of fundamentalitythe relation of space and time to quantum entanglement, and space and time in theories of quantum gravity. Only through consideration of a range of different approaches to the topic can we hope to get clear on the status of space and time in our contemporary understanding of physical reality.