The Ouse valley, East Sussex, is a key communication route from the Channel coast, via the Downs (and the historic county town of Lewes), to the wide expanse of the Weald. It traverses and encompasses landscapes and archaeological sites of both regional and national importance – all connected by the river Ouse and its valley. This is the first review of the archaeology of this important landscape – from Palaeolithic to medieval times by contributors all routed in the archaeology of Sussex. Binding together the archaeology is a review of the geoarchaeology and palaeo-environment following which the chapters document the collective archaeology and potential from the Palaeolithic of Boxgrove vs Piltdown, via Mesolithic archaeology from the textbook excavations of Grahame Clark to recent 21st century investigations. Monuments of causewayed enclosures, long barrows and round barrows represent some of the Neolithic and Bronze Age evidence with some extraordinary finds recorded in the Bronze Age. From hillforts and villas, to medieval rural and urban excavation; the Ouse valley represents a microcosm of the wider region, the contributions collectively reveal the importance and significance of this valley to the development of landscape history and society of a quintessential English county. The narrative concludes with the first detailed research agenda for the Ouse valley.