South Benfleet is a town and former civil parish, in the Castle Point district of Essex, England, 30 miles east of London. It is adjacent to the village of North Benfleet. The Benfleet (SS7) post town includes South Benfleet, Thundersley, New Thundersley and Hadleigh. The Battle of Benfleet took place here between the Vikings and Saxons in 894. In 1951 the parish had a population of 8191.