East Sussex is a county in South East England. It is bordered by the counties of Kent, Surrey and West Sussex and, to the south, by the English Channel.

The ancient kingdom of Sussex was divided into eastern and western administrative regions, with separate county councils, in 1888: the county town became Lewes. In the new Sussex East county there were three self-administered county boroughs: Brighton, Eastbourne and Hastings. In 1974 the new county of East Sussex was created: at which point the three county boroughs became districts within the county. At the same time the western boundary was altered, so that the Mid Sussex region (including Burgess Hill and Haywards Heath) was transferred to the administrative county of West Sussex.

In 1997, Brighton & Hove became a self administered unitary authority and was eventually granted city status in 2000.