An Bord Pleanála has approved plans by ESB and Bord Na Móna to erect 61 wind turbines on a 5,000 hectare site near Bellacorick in north Mayo.
The companies behind plans to construct the windfarm say they hope to begin construction work on the project next year.
When completed, the Oweninny wind farm would have a maximum electricity generating capacity of 172 megawatts.
The decision to allow the development follows an oral hearing in 2014 and a subsequent request for a revised Environmental Impact Assessment. This resulted in the companies reducing the scale of the proposed development from 112 turbines to 61.
Oweninny Power Limited said that while there would be fewer turbines, they would be larger and more efficient.
The developers say they are reviewing the conditions attached to the permission but that they hope the wind farm will be operational before 2020.
Costing over €320m, the wind farm will be constructed on lands owned by Bord Na Móna, around 30km west of Ballina and close to the former ESB power station at Bellacorick.
The planning board has ruled that the development would not have a significant adverse impact on the landscape or affect the integrity of any sites of environmental significance.
Permission has been granted subject to 20 conditions.
These include stipulations that power lines on the site be placed underground and that measures be taken to reduce the impact of "shadow flicker" from a number of turbines on nearby properties.
However, the permission is not contingent on an explicit condition that the developers contribute to a so-called Community Gain fund.
It was proposed at the oral hearing into the project that a payment of €10,000 per year would be made for every megawatt (MW) of power generated, to mitigate the impact of the development on the local community.
The Board says it notes and welcomes the applicant's proposal to pay a contribution of €1,000 per MW per annum for the operational life of the site. It says that in view of the developers' statements in this regard, there is no need to impose a condition regarding community gain funding.
The Oweninny development was one of two such proposed developments in north Mayo to come before An Bord Pleanála.
In May of last year, an application by Coillte to construct a 48-turbine wind farm at Cluddaun, near Moygownagh. was refused.