Port Waikato is a New Zealand parliamentary electorate which existed for four parliamentary terms from 1996 to 2008, and was recreated by the 2019/20 electoral redistribution ahead of the 2020 election. It was held by Bill Birch for one term, and by Paul Hutchison for the following three terms. From 2020, it was held by Andrew Bayly. All of these were members of the National Party.

During the campaign for the 2023 general election, the ACT Party candidate died. Only a poll for the party vote was held during this election; the electorate vote was determined in the 2023 Port Waikato by-election.

The 1996 election was notable for the significant change of electorate boundaries, based on the provisions of the Electoral Act 1993.^[1] Because of the introduction of the mixed-member proportional (MMP) electoral system, the number of electorates had to be reduced, leading to significant changes. More than half of the electorates contested in 1996 were newly constituted, and most of the remainder had seen significant boundary changes. In total, 73 electorates were abolished, 29 electorates were newly created (including Port Waikato), and 10 electorates were recreated, giving a net loss of 34 electorates.

The Port Waikato electorate was formed from parts of the Franklin, Raglan, and Waikato electorates, all of which were abolished.^[2] In its initial area, towns with more than one polling booth were Huntly, Pukekohe, Ngāruawāhia, Tuakau, and Waiuku. Localities with a single polling booth were Aka Aka, Awhitu, Bombay, Buckland, Glen Massey, Glen Murray, Glenbrook, Horotiu, Mauku, Meremere, Naike, Ohinewai, Onewhero, Orini, Otaua, Paerata, Pōkeno, Port Waikato, Pukekawa, Pukemiro, Pukeoware, Puni, Raglan, Rangiriri, Ruawaro, Taupiri, Te Ākau, Te Hoe, Te Kauwhata, Te Kohanga, Te Kowhai, Te Pahu, Te Uku, Waerenga, Waikaretu, Waikokowai, Waingaro, Waipipi, Waiterimu, Waitetuna, Whatawhata, and Whitikahu.^[3]

Bill Birch was the first representative of the Port Waikato electorate following the 1996 election. Throughout his long parliamentary career, which started in 1972, Birch always represented the electorate in which the town of Pukekohe was located, where he had established a business prior to entering parliament.^[4] When Birch retired at the 1999 election, he was succeeded by Paul Hutchison, a medical specialist. When the Port Waikato electorate was abolished in 2008, Hutchison transferred to the reconstituted Hunua electorate, which he represented until his retirement from politics at the 2014 election.^[5][6]

In the 2019/2020 boundary review, the Representation Commission recreated it. This was necessitated by significant population growth in South Auckland and the Waikato region. It was created out of the western portion of Hunua and the northwestern area of Waikato.^[7] Of the nine creations at that redistribution, it was one of the four included in the initial proposals.^[8]

In 2023, Neil Christensen, who was a candidate for the ACT Party, died during the advance voting period. This triggered the Port Waikato by-election for the candidate vote, which will be held on 25 November 2023.^[9]