The Wealden Group of southern England was deposited by rivers, on floodplains and in lagoons during the Early Cretaceous. Two historically significant ankylosaurs, Polacanthus and Hylaeosaurus, are currently known from its deposits; Hylaeosaurus from the ‘lower Wealden fauna’ and Polacanthus from the ‘upper Wealden fauna’. Here, we describe a new genus and species of ankylosaur from the Wessex Formation of the Isle of Wight, which is characterized by numerous postcranial autapomorphies.