Local Sinn Féin TD Matt Carthy has been appointed to the Public Accounts Committee.
The PAC has overall responsibility for ensuring public services are run efficiently and achieve value for money.
Deputy Carthy, who was first elected to the Dáil in February, is already a member of the special Covid-19 oversight committee of TDs.
He was also appointed to the Sinn Féin frontbench as its agriculture spokesman.
Laois-Offaly TD Brian Stanley has already been appointed chair of the PAC.
Membership of the other Oireachtas committees isn’t expected to be finalised until after the summer recess.