New Zealand Railways Corporation (NZRC) is the state-owned enterprise that owns the land beneath KiwiRail's railway network on behalf of the Crown. The corporation has existed under a number of guises since 1982, when the old New Zealand Railways Department was corporatised followed by deregulation of the land transport sector. In 1986, the Corporation became a State-owned enterprise, required to make a profit. Huge job losses and cutbacks ensued, and the rail network, rail operations and ferry service of the corporation were transferred to New Zealand Rail Limited in 1990. The Corporation retained ownership of the land beneath the railway network, and charged a nominal rental to New Zealand Rail, which was privatised in 1993, and renamed Tranz Rail in 1995. In 2004, following a deal with Tranz Rail's new owners Toll NZ, the Corporation took over responsibility for maintaining and upgrading the rail network once more, trading under the name ONTRACK. Negotiations with Toll over track access charges concluded after four years with no agreement reached, so the government purchased the entire rail and ferry operations, naming the service KiwiRail. ONTRACK's railway infrastructure and employees were then transferred to KiwiRail in 2008, which itself was initially a subsidiary of the corporation. On 31 December 2012, the Corporation once again became the landowner.

KiwiRail Holdings Limited is a New Zealand state-owned enterprise (SOE) responsible for rail operations in New Zealand and operates inter-island ferries. Trading as KiwiRail and headquartered at 604 Great South Road, Ellerslie, KiwiRail is the largest rail transport operator in New Zealand. KiwiRail has business units of KiwiRail Freight, Great Journeys New Zealand and Interislander. The company was formed in 2008 when the government renationalised above-rail operations and inter-island ferry operations, then owned by Toll Holdings. In 2021, the government launched the New Zealand Rail Plan, with funding for rail projects to come from the National Land Transport Fund (NLTF), and with KiwiRail remaining an SOE but paying Track Access Charges (TACs) to use the network.