The New Plymouth Night Express was a passenger express train operated by the New Zealand Railways Department (NZR) that ran between Auckland and New Plymouth. It ran in various forms from 1933 until 1983, though the Express designation was lost in 1956 and later incarnations did not operate at night and terminated in Taumarunui rather than Auckland. The New Plymouth Night Express should not be confused with the New Plymouth Express that operated between New Plymouth and Wellington.
In 1933, the Stratford - Okahukura Line was completed, providing a rail link through northern Taranaki between the Marton - New Plymouth Line and the North Island Main Trunk Railway. On 4 September 1933, the new line's ownership was handed over to NZR from the New Zealand Ministry of Works, and early that morning, the first passenger service was operated. This inaugural service left Auckland at 7pm on 3 September 1933 attached to the Night Limited, and it consisted of one first class carriage, one second class carriage, a sleeping car, and a guard's van. In Taumarunui, these carriages were detached from the Night Limited, as it was to continue to Wellington, and ran as a separate train to New Plymouth, departing Taumarunui at 12:45am and arriving in New Plymouth just after 6am. The return working left New Plymouth at 7:10pm, connected with the Night Limited in Taumarunui, and was conveyed back to Auckland by the Limited for a 7:10am arrival.
Joint running with the Night Limited for the Tauramunui-Auckland leg was the pattern for the 1930s, with the service provided thrice weekly on Mondays, Wednesdays, and Fridays.AB class steam locomotives were typical motive power at this stage, and a train from Hawera connected with the Express in Stratford. At holiday times, the New Plymouth Night Express was run separately from the Night Limited due to large volumes of passengers, and as this service ran directly between New Plymouth and Auckland, it did not pass through Taumarunui, which is seven miles to the south of the junction in Okahukura; accordingly, a connecting train ran between Taumarunui and Okahukura.