Until the early 19th century, Sedbury was usually known as Sudbury, a name derived from "south fortification", referring either to Offa's Dyke or a Roman settlement in Sedbury Park. The development of the village began during the First World War, when a prisoner of war camp of concrete huts was built north of the main road at what is now Grahamstown Road. Later, huts were built for Royal Engineers working to establish the National Shipyard at Beachley, and houses were constructed at Pennsylvania Farm (now Mercian Way). Development in the mid-20th century included more housing, shops, a pub and schools close to the main road. Further development was proposed in 2013.