|Locale||Waikato, New Zealand|
|First service||26 June 2000|
|Last service||7 October 2001|
|Former operator(s)||Tranz Scenic|
|Distance travelled||134.75 kilometres (83.73 mi)|
|Average journey time||124 minutes|
|Service frequency||daily return|
|Rolling stock||NZR RM class (Silver Fern)|
|Track gauge||3 ft 6 in (1,067 mm)|
The Waikato Connection was a short-lived express passenger train between Hamilton and Auckland in New Zealand's North Island. It consisted of a single weekday return service using diesel multiple unit railcars.
The service commenced as a six-month trial on 26 June 2000 and was primarily aimed at business people who regularly commuted to work in Auckland. It used Silver Fern railcars with full onboard catering and stopped at the intermediate stations of Huntly, Pukekohe, Papakura, Middlemore, and Newmarket.
Four months into the trial the service was reported to be "performing up to expectations" and was later extended beyond the trial period.
Tranz Rail announced in October 2000 that it intended to exit the passenger rail business to concentrate on its freight interests. The new owner of Tranz Scenic, two directors of West Coast Railway in Australia, had limited purchase funds, and so were only prepared to purchase the most profitable services, prompting Tranz Rail to terminate those services that were not purchased, including the Waikato Connection. It was officially cancelled on 7 October 2001 along with the Geyserland Express, the Kaimai Express, and the Bay Express. A replacement Tranz Metro service between Auckland and Pukekohe commenced the following day.
Efforts were made to save the service prior to its cancellation, including an investigation made by Environment Waikato into the possibility of subsidising it. The Council, which at the time had a policy of not subsidising rail services, decided against providing funding as it was deemed to be too expensive. An approach was also made to the Government for funding, especially in light of the subsidy that they had extended for the Southerner, but this was also declined. West Coast Railway reported that the Waikato Connection was "the most unprofitable service" but that they would be prepared to consider retaining it with community support which they expected would be needed for about three years.
At the time of its cancellation the Waikato Connection was being patronised by an average of 129 passengers per trip, most of which boarded at Pukehohe or Papakura, with only about 30 of those travelling the full distance between Hamilton and Auckland. Some considered the cancellation premature as the service was beginning to grow in popularity. 
A refurbisheed NZR RM class (88 seater) nicknamed the 'Blue Streak' was used for a trial Hamilton-Auckland service from 8 April 1968, which was discontinued for lack of patronage.
After the June 2006 announcement of the Overlander's cancellation, there were proposals to re-instate the Waikato Connection, including from Dave Macpherson, Hamilton City Council's Passenger Transport Committee chairman. The Overlander's cancellation was subsequently rescinded, eliminating the possibility of using its rolling stock on a new Waikato Connection, but other proposals have remained due to increasing vehicular traffic volumes straining road capacity. These proposals include using the Silver Ferns as in the original Waikato Connection, though they were at the time under contract for suburban commuter trains between Auckland and Pukekohe. The most recent proposal from the Rail Working Group recommends the use of Silver Fern railcars operating a service between Hamilton and Auckland Railway Station, possibly also with a shuttle service at the Auckland terminus to points around the Auckland CBD. This proposal addresses cost concerns raised by the affected local government organisations by making use of existing rolling stock and infrastructure where possible and avoiding use of the Britomart Transport Centre which, because of capacity constraints, is not available for peak-time arrivals and departures of such a service.
The primary difficulties facing the proposal are lack of rolling stock, lack of a commercially viable business case (requiring support from local and central government for subsidies) and train paths through the Auckland suburban area into the Britomart Transport Centre. The proposal was dropped on a 2011 report in favour of extension only from Pukekohe to Tuakau. In 2016 the Transport Minister said, when starting work on a parallel section of Waikato Expressway costing over $2bn, "it will be some time before it makes its case economically".
A further study to establish a strategic business case was started in 2017.
- Rutherford, Ross (August 2005). "Preliminary Feasibility Study into Passenger Rail Services in the Hamilton Area" (PDF). Environment Waikato and Hamilton City Council. Hamilton Alternatives to Roading Transportation Study. Transport Planning Solutions. p. 15.
- Wheeler, Bob (11 October 2000). Chairman’s Address to Shareholders, 2000 Annual Meeting. Wellington: Tranz Rail Holdings.
- "Mayor disappointed Waikato Connection axed" (Press release). Hamilton City Council. 27 June 2001. Retrieved 20 October 2010.
- BROWN, Jo-MARIE (6 October 2001). "Regional rail services disappear". NZ Herald. APN Holdings NZ. Retrieved 21 October 2010.
- "Regional Council to meet on Waikato rail connection" (Press release). Environment Waikato. 24 August 2001. Retrieved 21 October 2010.
- "Setback in Hamilton-Auckland commuter train dream, Greens say". Stuff (Fairfax Media). 1 July 2015.
- LEAMAN, AARON (11 May 2011). "Strand rail link 'best'". Waikato Times. Hamilton: Fairfax New Zealand. Retrieved 12 May 2011.
- "Bridges backs commuter rail". Stuff. Retrieved 2016-10-18.
- "Regional council committee supports fresh look at commuter rail". Waikato Regional Council. Retrieved 2017-05-16.