Ancient Water Supply and Management Systems in the Western Mediterranean brings together a wide range of approaches dealing with the connection between settlements and water from the Iron Age to the Late Antique period. It focuses on different infrastructures built to collect and control water from various sources: groundwater, rainwater and surface water. Vital to both human survival and a plethora of crafts and social activities, ensuring a steady supply of quality water was paramount to any settlement in Antiquity. Conversely, an excess of water also entailed drawbacks and, eventually, dangers, leading to the creation of drainage systems. Some of these systems were designed at the same time as the settlements themselves, whilst others are the result of needs that evolved over time. Collectively, these structures aimed to harness naturally occurring waters and greatly transformed the landscape. The contributions that make up this volume, coming from Portugal, Spain, France and Italy, include spatial and territorial studies, and site and question-specific case studies aiming at a broader understanding of the transformative effect and relationship these settlements had with this natural resource. The features under investigation include urban water distribution and drainage systems, aqueducts, wells, cisterns and dams, alongside broader considerations on religious and operational dimensions of these infrastructures.