A Las Vegas-style casino, betting and leisure complex complete with horse and greyhound tracks and a chapel has been given the green light by planners.
The 460 million euro Tipperary Venue, near Two-Mile Borris, will have a 500-bed hotel - the largest in Ireland - a health spa and swimming pool, an equestrian centre and an 18-hole golf course.
But plans for a money-spinning 15,000-capacity concert hall have been rejected, with An Bord Pleanala warning it was inappropriate considering the rural location.
The idea is being driven by Richard Quirke, owner of the Dr Quirkey's amusement arcade in Dublin's O'Connell Street, and local Independent TD Michael Lowry.
The Tipperary deputy said the planning decision would help unleash the enormous potential of the site.
"In the context of stated Government policy to encourage creativity and job creation, this is a timely opportunity to progress an original plan which will generate enormous economic activity and create thousands of sustainable jobs," he said.
"A combination of a broad range of interactive projects on the one site will transform the economic, cultural and social life of Tipperary and the entire region."
Mr Lowry insisted the finance was in place and the entire development would go ahead.
Renowned racehorse trainer Aidan O'Brien backs the plan and suggested it would eventually be a rival to host the United States' multimillion-dollar Breeders' Cup fixture.
The 800-acre development is opposed by An Taisce, a handful of local residents and anti-gambling bodies including the Ireland Against Casinos group, which fought a development on the old Phoenix Park racecourse.