Aupito Tofae Su'a William Sio (born 1960)[2] is a politician who became a member of the New Zealand House of Representatives on 1 April 2008[3] for the Labour Party as a list MP.

[1] 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.

[13] 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.

[18] 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.

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.

"[23][24] On 10 February 2023, Sio was granted retention of the title "The Honourable" for life, in recognition of his term as a member of the Executive Council.

[25] Sio's stance against the Marriage Amendment Act, which allowed same-sex couple to marry, was not popular among his Labour colleagues.