Transport Infrastructure Ireland (Irish: Bonneagar Iompair Éireann) is a state agency in Ireland, dealing with road and public transport infrastructure. The body was established in 2015 from a merger of the Railway Procurement Agency into the National Roads Authority, with the latter being assigned the new operational name of Transport Infrastructure Ireland (TII).

The National Roads Authority (NRA) was established in 1994 to provide central management for Ireland's national road network, while the Railway Procurement Agency (RPA) was founded in 2001 to arrange for new light rail and metro projects. The RPA was merged into the NRA under the Roads Act of 2015, and the body was operationally named, and publicly rebranded, as Transport Infrastructure Ireland.

The body owns the Luas and the planned MetroLink railway, but they are leased to private operator Transdev.

The agency, technically a "non-commercial semi-state body", looks after certain major roads, and some forms of light and metro rail infrastructure, and related services. It is distinct from, but subject to the same government department as, the National Transport Authority and the Commission for Railway Regulation.

• Transport Infrastructure Ireland website