The City Council currently has 350 vacant houses in its portfolio, while the County Council has 184.
That's according to research conducted by Aontú Leader Peadar Tóibín - under the Freedom of Information Act.
Nationally, more than 3,500 council-owned houses are empty at present.
The figures also show that nationally there are 98,171 people on housing waiting lists.
Dublin City Council owns the most vacant houses - 712 - followed by Cork City Council in second and and Cork County Council in fourth.
The average time taken to re-let council homes has increased steadily since 2018 - and, in 2021, averaged almost eight months.
Aontú Leader Peadar Tóibín claims 'bureaucracy, red tape, poor management, lack of staff and inefficiency is making housing provision grindingly slow'.
