Northern Ireland Transport Holding Company (NITHC) is a public corporation established under the Transport Act (NI) 1967 to oversee the provision of public transport in Northern Ireland. It took over the railway and bus activities of the Ulster Transport Authority (UTA), thus, Northern Ireland Railways and Ulsterbus were incorporated.

In 1973 Citybus (now Metro) was incorporated to take over the bus services of the Belfast Corporation Transport Department. Translink is a brand name which was introduced in late 1996 to cover the integrated services of Ulsterbus, Citybus (now Metro) and Northern Ireland Railways.