The development, to be built in Clongriffin, north Dublin, will become Ireland's largest Muslim Cultural Centre catering to the 40,000-strong community living in the capital.
The application to Dublin City Council was submitted by an organisation called the Dublin Welfare Society.
It was approved by planners and will cost a staggering €40m, which is believed to be coming from a backer in the United Arab Emirates.
Clongriffin is a new town on the northern fringe of Dublin city.
It was planned for widescale development at the end of the Celtic Tiger era and while many homes and apartments were built in the area, there are large stretches of wasteland and some ghost estates.
The planned mosque will have a three-domed cultural centre and conferencing facilities as well as primary and secondary schools onsite.
The 157,000 sq ft development will also include a 130- seat restaurant, some apartments and landscaped gardens.
It will cater for 550 people for Friday prayers and as many as 3,000 for the Eid festival.
The land near Clongriffin DART station is a vacant plot owned by developer Gerry Gannon.
A condition of the planning permission is that the call to prayer is not audible outside the Mosque area.