The fire took hold shortly before 8:30 pm last night (Tuesday) at an empty building on the Edmonstown Road in Ballyboden.
The building was once owned by the Augustinian Order.
Several units of the fire brigade worked to bring the fire under control at the former church and religious college that was once owned by the Augustinian Order.
The site had previously been granted permission for 400 apartments.
The blaze destroyed the roof and windows
Sinn Féin councillor Róisín Mannion says misinformation has been spread in the aftermath that the site was due to accommodate asylum seekers.
This afternoon, investigating Gardai remain at the scene and are appealing for anyone who was in the area at the time, and may have seen anything suspicious, to contact them.