The €200m Corrib Gas Field project was tonight approved by An Bord Pleanala.
Locals had objected to the controversial plan, which would necessitate the excavatation of 450,000 cubic metres of peat from the site earmarked for 160-hectare gas refinery in Mayo.
The developers, Shell and EP Ireland Ltd, are now free to continue work on the gas refinery in Bellagelly, Co Mayo and a 117-hectare peat deposition site in Srahmore, County Mayo.
Locals had appealed to An Bord Pleanala after it was granted planning permission by Mayo County Council last year.
The Bord tonight granted permission to the project with certain conditions.
In its report, it said the Corrib Gas field development:
:: would not be unduly injurious to the amenities of the area or property in the vicinity
:: would be acceptable in terms of traffic safety
:: would not be prejudicial to public health and safety
:: would be in accordance with the proper planning and sustainable development of the area.