Iron Age people established a promontory fort overlooking the sea at Shanoon (referred to in 1832 as meaning the 'Old Camp' but more likely Canon Power's Sean Uaimh, 'Old Cave') at a point known for centuries as Black Nobb, where the old pilot station now stands, and underneath which a cave runs. Henceforth the place was referred to as Dun Mor, the Great Fort.
Fish was an important part of the people's diet, and for hundreds of years a fishing community lived here.
In 1640, Lord Power of Curraghmore, who owned a large amount of property in the area, built a castle on the cliff overlooking the strand about two hundred metres from St. Andrew's Church. The castle was falling into ruin by the middle of the next century and now just one tower remains.
The old church of Killea (Cill Aodha — Aodh's Church, Aodh is Irish for Hugh) is thought to have been built in the twelfth century and one wall still stands, opposite the Roman Catholic church of The Holy Cross, at the top of Killea hill.
In Smith's history of Waterford, the village was mentioned as being a fishing port about the year 1745. The fishermen's homes were situated in the Lower Village near the Strand Inn and boats were launched from the slip at Lawlor's Beach before the harbour was built. There is mention of a fleet of fifty fishing boats working from Dunmore East in 1776.
In 1812 a decision was made at Westminster to create an entirely new landing point for passengers and mails coming to Ireland from London and southern England. The location selected was Dunmore East and £118,000 was set aside for the erection of a pier there. In 1814 dramatic changes took place when Alexander Nimmo, the Scottish engineer (builder of Limerick's Sarsfield Bridge) commenced work on the new harbour at Dunmore to accommodate the packet station for ships, which carried the Royal Mail between England and Ireland. The work consisted mainly of a massive pier or quay with an elegant lighthouse at the end. Nimmo's original estimate had been £20,000 but at the time of his death in 1832 about £93,000 had been spent and the final cost was £108,000. By then (1837) the harbour had started to silt up, and the arrival of steam meant that the winding river could be negotiated easily, so the packet station was transferred to Waterford.
The great sheltered harbour then constructed meant that Dunmore East was to gradually become an important fishing port. It also then developed into a very popular tourist resort and it is now a favourite port of call for large cruise liners visiting the south east of Ireland.
The Haven Hotel, formerly the Villa Marina, was a holiday home built by the Malcolmsons, who were involved financially in the American Civil War. The Fisherman's Hall in the village was also built by the family for fishermen to mend their nets.
Dunmore East is home to many sporting clubs from sailing to Gaelic Football. Gaultier GAA which focuses primarily on Gaelic Football is located just outside the village, across the road from Dunmore FC soccer club. Gaultier were founded in 1927 and compete in the Waterford Senior Football Championship as well as catering for over 100 juvenile members. Dunmore FC were founded in the 1970s initially before being re-established in the early to mid 2000s. The sailing club was founded in 1934.
The harbour is one of the five designated National Fishery Harbours, and has the second highest figure for fish landings after Killybegs. In the summer months it is popular with visiting yachts which have a designated pontoon.
Dunmore East is noted for:
A plan was developed in 2005 by Waterford County Council to expand the harbour to accommodate more recreational marine activities. However that plan appears to have been shelved due to lack of funding.
The village is home to the Waterford Harbour Sailing Club with dinghy and keelboat sailing and the Dunmore East Adventure Centre. The local golf course is located on the cliff top overlooking the bay.
Sea angling and Diving is catered for by Dunmore East Angling Charters.
Dunmore East is also home to some of the best seafood restaurants in Ireland.
Two principal hotels are located in Dunmore: The Strand Inn and The Haven. The Haven was the summer home of the Malcolmson family of Portlaw who were wealthy millers and shipbuilders.
There is a caravan site catering for motorhomes and touring caravans.
The most popular event in Dunmore East is the annual bluegrass festival which takes place at the end of August. During this festival the village hosts a number of bluegrass groups over the weekend during which almost every bar becomes a music venue from 3pm until late in the evening.
There is a good road connection to Waterford City. Suirway operate a bus route linking Dunmore East to Waterford.