The development, which will comprise a major shopping complex with Dunnes Stores as the anchor tenant, will be located on a 43-acre site, where Glanbia was formerly located, close to Dungarvan town centre.
It will also include apartments, a restaurant, night club, four-screen cineplex, and will have car-parking facilities for several hundred vehicles.
Some 230 additional jobs will be created during the construction stage, which will take at least two years.
The weekend decision to uphold the massive Dungarvan development has been warmly welcomed in the county town, and brings to an end a protracted and controversial saga.
"It will give the economy of the whole area a massive boost, and the 350 permanent new jobs that will be created will be a godsend," said Mayor Nuala Ryan.
Her sentiments have been echoed by town and county councillor Billy Kyne, who had been the most outspoken public representative in denouncing the objectors to the development.
"It would have been nothing short of a disaster had this massive development been lost to Dungarvan, on the grounds of what to me were very frivolous objections," he said.
A total of 32 conditions are attached to the Bord Pleanála approval, but they are not expected to present insurmountable obstacles for developers Clancy Construction Ltd of Thurles.
One of the conditions will however prevent the developers from demolishing three houses at O'Connell Street, which would have provided easy access to the Shandon site.
Affirming the town council decision, An Bord Pleanála stated that "subject to compliance with all the conditions we have set, the proposed development will be an appropriate one for this location and will not seriously injure the amenities of other property in the vicinity.
"It is a project that is in accordance with the proper planning and sustainable development of the area."
The development has been delayed by a series of planning difficulties. Originally the town council granted full planning permission, but bodies such as An Taisce, the Friends Of The Environment and RGDATA the Retail, Grocery, Dairy and Allied Trades' Association objected to it.