William Sio

In mid-December 2022, Sio announced that he would not be contesting the 2023 New Zealand general election and would step down at the end of the 2020–2023 term. He attributed his resignation decision to his family and matai (chiefly) responsibilities, stating that his job as a Member of Parliament was "all-consuming and relentless."

During the 2020 general election, Sio was re-elected in Māngere by a margin of 19,396 votes, defeating National's candidate Loheni.

Sio was re-elected during the 2017 general election by a margin of 14,597 votes, defeating National Party candidate Agnes Loheni. Following the formation of Labour-led coalition government with New Zealand First and the Greens, Sio was appointed as a Minister outside Cabinet by the Labour Party caucus. On 26 October 2017, Sio was appointed Minister for Pacific Peoples, Associate Minister for Courts, and Associate Minister of Justice.

In 2013, Sio voted against the Marriage Amendment Bill, which aimed to permit same sex marriage in New Zealand, with fellow Labour MPs Rino Tirikatene, Ross Robertson and Damien O'Connor, alongside New Zealand First, Brendan Horan (former New Zealand First MP), and 32 National MPs. The Bill passed, becoming law.

Aupito Tofae Su'a William Sio (born 1960) is a politician who became a member of the New Zealand House of Representatives on 1 April 2008 for the Labour Party as a list MP. Since the November 2008 election, he has represented the Māngere electorate.

In the 2005 parliamentary election Sio was ranked 47th on the Labour party list and failed to be elected by two places. However Labour Party list MP Dianne Yates left the Parliament on 29 March 2008, and Sio was declared elected in her place (the person above him on the list, Louisa Wall, had already been declared elected to replace Ann Hartley).

In the 2008 general election Sio won the Māngere electorate, defeating the incumbent independent (and former Labour) MP Taito Phillip Field by 7,126 votes. In the 2011 and 2014 elections, Sio's majority was approximately 15,000 votes.

Sio served as a Manukau City Councillor, representing the Ōtara ward from 2001. Sir Barry Curtis, the Mayor of Manukau City, selected Sio as chair of the planning committee in November 2004. In October 2007, the newly elected Mayor of Manukau City, Len Brown, appointed Sio deputy mayor, making him the first Pacific Islander to hold the position in Manukau City.

While growing up in New Zealand during the 1970s, Sio and his family experienced a police dawn raid, which disproportionately targeted members of the Pasifika communities. Sio recalled that he was personally traumatised by the raid and that his father, who had recently bought the house, was helpless.

After Prime Minister Jacinda Ardern confirmed that the New Zealand Government would apologise for the Dawn Raids of the 1970s and early 1980s, Sio gave an emotional testimony of his family's experiences with a dawn raid, stating that the apology restored mana for the victims of these raids.

Sio is a Samoan who was born in Samoa and came to New Zealand in 1969. He has the matai (chieftain title) of Aupito from the Matatufu village of the Lotofaga district on the island of Upolu. He belongs to the extended family called Aiga Sa Aupito, which he now heads, as his father, Aupito Pupu Sio, bestowed the title in a 'fa'aui le ula' from father to son. Sio is a Mormon and has served as one of their bishops. He is married with a family of adult and young children.