Helensville was a New Zealand parliamentary electorate in the Auckland region, returning one Member of Parliament to the House of Representatives. The electorate was first established for the , was abolished in 1984, and then reinstate for the . The seat was won and held by John Key through his term as prime minister. Chris Penk of the National Party held the seat from the 2017 general election until its abolition in 2020, when it was replaced with the new Kaipara ki Mahurangi electorate. Population centres The 1977 electoral redistribution, initiated by Robert Muldoon's National Government, was the most overtly political since the Representation Commission had been established through an amendment to the Representation Act in 1886. As part of the 1976 census, a large number of people failed to fill in an electoral re-registration card, and census staff had not been given the authority to insist on the card being completed. This had little practical effect for people on the general roll, but it transferred Māori to the general roll if the card was not handed in. Together with a northward shift of New Zealand's population, this resulted in five new electorates having to be created in the upper part of the North Island. The electoral redistribution was very disruptive, with 22 electorates being abolished, and 27 (including Helensville) being newly created or re-established. These changes came into effect for the . In the 1983 electoral redistribution, the Helensville electorate was abolished, and its area went to the and electorates. Helensville was re-established in time for the 2002 election in response to continued high population growth in and around Auckland. It was formed from the northern flank of the Waitakere electorate with the addition of areas from the Rodney electorate around its southern boundary. Helensville covers an area of the rapidly growing northern Auckland urban fringe, drawing Helensville and Kumeu from the former Rodney District, moving south to take in Paremoremo, Greenhithe and Albany from the former North Shore City, and finally tacking west to include Whenuapai, Hobsonville and West Harbour from the former Waitakere City. The boundaries of the electorate changed significantly in the 2019/20 boundary review. Its northern boundary moved northward to become the same as the boundary between the Northland and Auckland local government regions, taking in part of the electorate and all that part of Rodney electorate north of Waiwera, which is, by area, most