The area around Eastbourne is known to have been settled throughout history - artefacts dating to the Stone Age have been found in the surrounding countryside, and there are both Roman and Anglo-Saxon sites within the modern boundaries of the town; some even speculate that it was a major Roman settlement. 'Eastbourne' was granted the right to hold a market in 1315, three years after a comparable grant at Brighton. However, it remained an area of small rural settlements until the 19th Century, with 4 villages or hamlets occupying the site of the modern town: Bourne (or, to distinguish it from others of the same name, East Bourne), surrounded the "bourne" (stream) which rises in what is now Motcombe Park, and is now known as Old Town; Meads, where the Downs meet the coast; South Bourne; and the fishing settlement known simply as Sea Houses.

By the mid-19th Century most of the area had fallen into the hands of two landowners: John Davies Gilbert (the Davies-Gilbert family still own much of the land in Eastbourne and East Dean) and William Cavendish, Earl of Burlington. Encouraged by the growing appreciation of the seaside sparked by Richard Russell's assertion of its medicinal benefits some decades earlier, these were to oversee the creation of "the empress of watering places". An early plan, for a town named "Burlington", was abandoned, but in 1849 the London, Brighton and South Coast Railway arrived, and the town's growth accelerated. Cavendish, now the 7th Duke of Devonshire hired Henry Currey in 1859 to lay out a plan for what was essentially an entire new town — a resort built "for gentlemen by gentlemen". The town grew rapidly — from a population of less than 4000 in 1851 to over 22000 by 1881 — and in 1883 was incorporated as a "municipal borough"; a purpose-built town hall was opened in 1886.

Eastbourne pier and beachThis period of growth and elegant development continued for several decades, but World War II saw a change in fortunes: initially, children were evacuated to Eastbourne on the assumption that they would be safe from German bombs, but soon they had to be evacuated again. Pilots wishing to off-load unused munitions before crossing the channel found such coastal towns useful targets, and many original Victorian buildings were damaged or destroyed.

After the war, development continued, including the growth of Old Town up the hillside and the housing estates of Hampden Park (above the park itself, named after Viscount Hampden, whose grandson sold the land to the council), Willingdon Trees and Langney. Throughout the 20th Century, there were controversies over the loss of historic landmarks or natural features, and over particular buildings, such as the glass-plated TGWU headquarters on the sea-front, and the 22-storey "South Cliff Tower". In 1981, a large section of the town centre was replaced by the indoor shops of the Arndale Centre.

In the 1990s, however, both growth and controversy accelerated rapidly as a new plan was launched to develop the area known as the "Crumbles", a shingle bank on the coast to the east of the town centre. This area, now known as the "Sovereign Harbour" and containing a marina, shops, and several thousand houses, was formerly home to many rare plants. Together with continued growth in other parts of the town, and the taming of the central marshland known as the "levels" into farmland and nature reserves, this has turned Eastbourne into the centre of a conurbation, with the appearance from above of a hollow ring.