The state paid private landlords more than 528 million euro last year under two social-housing schemes.
They got 382 million euro under the Housing Assistance Payment, and over 145 million under the Rental Accommodation Scheme.
Under both schemes, most of the rent is paid by councils, with the tenant making up the balance.
Fianna Fáil's housing spokesman, Darragh O'Brien, says money is being wasted and could be better spent on actually building social housing units.
Soc Dems Wicklow TD Blasts €19B Electricity Network Upgrade Amid Rising Household Costs
Water Infrastructure Project Plans To Shore Up Wicklow Supply For Decades To Come
Go-Ahead Ireland to Create 400 Jobs Boosting Public Transport in Wicklow
Pat Devlin Calls Time After Four Decades With Bray Wanderers
Wicklow Musician Earns National Business Award For Merging Traditional Culture And Wedding Celebration