There is evidence of habitation in this area during the late Stone Age, Bronze Age and Early Christian periods. Around the 3rd century a tribe called the 'Decie' were dispossessed of their lands in Tara Co. Meath and settled in this area westward to the Cork borders. This area is still known as Na Deise (in English The Decies.) Saint Garvan is credited with founding the original settlement of Dungarvan. He was a disciple of Saint Finbarr and is known to have founded the monastery of Achadh-Garbhain in the 7th century.

It is thought that there was a small Viking trading settlement, possibly at Shandon on the banks of the Colligan river, to the north of the present town. A carved bone, Viking pattern, trial piece from the 9th/10th centuries was found in this area (now in the National Museum, Dublin). The town really owes its foundation and development to the Anglo-Normans in the 12th century. They erected a motte and bailey at Gallows Hill to the west of the town and constructed a substantial castle through which they could control the port. Dungarvan was strategically located and was an important outpost and market centre for the hinterland.

Dungarvan was granted its charter in July 1215 by King John granting it the laws of Breteuil in France. In the 13th century Dungarvan was glowing into a prosperous settlement. The exchequer returns for 1262-3 indicate that it was a town of considerable wealth and prosperity. It was trading with England, especially Bristol and with the Continent. The most important export from Dungarvan was fish which was sent to Liverpool, Chester, Bristol, etc., indeed the majority of the population were employed in various aspects of this industry.

In an Act of Parliament of 1463 Dungarvan was described as 'the most great and ancient honour belonging to the King in Ireland'. In the 16th century Dungarvan was attacked several times and in 1582 most of the buildings were destroyed. As a result the town went into decline, the trades of the inhabitants noted in 1583 were mostly unskilled and agriculturally based e.g. fishermen, yeomen, butchers etc., one goldsmith is mentioned, there was a notable lack of skilled craftsmen and mercantile trades.

Dungarvan received a new Charter of Incorporation as a borough from James 1 in 1610. In 1611 Dungarvan was described as 'a poor fishertown of which the chief trade was fish taken there'.

Dungarvan featured prominently in the mid 17th century Civil Wars. In 1642 Sir William St. Leger, Lord President of Munster attacked the town and many of the citizens were killed. Soon after, the castle was retaken by the Irish. Over the next few years Dungarvan became one of the Confederate's main ports and ships were sent to Spain and other pIaces for arms and supplies. In 1647 Lord Inchiquin attacked Dungarvan but only recaptured it after a fierce siege lasting several days which destroyed the town. Sir Philip Perceval commented in 1647 that there were . . 'no inhabitants or stuff in any of the houses ..' Cromwell reached Dungarvan on the 4th December 1649, however, the town had surrendered the day before to Lord Broghill.

The Census of Ireland 1659 gives the population of Dungarvan as 213 and 44 in Abbeyside.

At the beginning of the 18th century the town was in a state of decay without a sufficient water supply or quay. In 1752 Dr. Pococke described it as a ..'good fishing town and famous for the export of potatoes to many parts of Ireland.' In the late 18th century it was described as a small seaport with little trade and inhabited mostly by fishermen. All this was to change with the reconstruction of Dungarvan by the 5th and 6th Dukes of Devonshire at the beginning of the 19th century. This work included a spacious new square, fish and meat markets and a new bridge over the river Colligan to connect the town with the suburb of Abbeyside. A substantial new quay was also built which was a major boost to shipping and commerce.

By 1832 the Boundary Commission noted that Dungarvan was in a 'prosperous and improving state, was neat in appearance and a popular sea resort.' The fisheries were still a major source of employment for about 4,000 of the inhabitants.

The Famine period in the 1840s had a disastrous effect on the town, drastically reducing the population and those who could afford it emigrated. In 1854 the Towns Improvement Act was adopted and Town Commissioners elected. It wasn't until the 1860s that the town began to recover and prosper, several new buildings were constructed and a Gas Works established.

In 1878 the Waterford, Dungarvan, Lismore railway was opened and this helped to develop the commercial life of the town. The town went into commercial decline towards the end of the 19th century, however it became increasingly popular as a sea resort and a new Esplanade and Park were laid out. The chief trade of the port in the early 1900s was in the export of timber. Somewhat later in the present century a tannery and milk processing plant were set up in the town and these dominated the commercial life of the town until recently.

Milk processing prospered and eventually grew into Waterford Co-Operative Society, one of the major agricultural Co-Ops in the country. Unfortunately the merger of Avonmore Foods with Waterford Foods in 1997, has placed a large question mark over the future importance of the Co-Op to the town. Extensive rationalisation plans have been proposed for the merged company.

Dungarvan Crystal, a subsidiary of Waterford Glass is another major manufacturing industry in Dungarvan and both it and the aforementioned Waterford Foods have spawned smaller subsidiary industries such as Radley Engineering and Ring Crystal. Two subsidiary plants of internationally renowned Pharmeceutical companies Smithkline Beecham and Stafford Miller, together with Waterford Joinery form the industrial base of modern Dungarvan.

The present population at about 7,000 is Still substantially less than the 8,625 in 1841 prior to the Great Famine. Tourism and recreation form a growing sector of the economic base of the town as the end of the 20th century approaches.