Cooper is of
Ngāti Māhanga descent, an iwi of
Waikato Tainui. He received his tertiary education at the
University of Auckland, graduating with
Bachelor of Laws (
Hons) and
Magister Juris (Dist) degrees in 1979. After university, he worked for Butler White & Hanna, where he became a partner in 1983; the law firm merged with
Simpson Grierson where he remained a partner. From 1997, he practised as a
barrister sole. He was principal legal advisor for three Auckland territorial authorities:
Auckland City Council,
North Shore City Council, and
Rodney District Council. In the 2000 appointment round, he was appointed
Queen's Counsel alongside six others. In 2004, Cooper was appointed a high court judge by the
attorney general,
Margaret Wilson, and sat in Auckland from August that year. Following the
2011 Christchurch earthquake, Cooper was appointed by the government to chair the
Canterbury Earthquakes Royal Commission; the other commissioners were engineers
Ron Carter and
Richard Fenwick. He was appointed a judge of the Court of Appeal in 2014, and was named to replace
Stephen Kós as president of the Court of Appeal from 26 April 2022. Cooper was on the executive of the Auckland Division of the
Cancer Society of New Zealand. He was on the establishment board for
Metrowater, which was formed in 1997 and has since been integrated into
Watercare Services. Cooper was board member for the
Museum of Transport and Technology and the
Auckland Observatory and Planetarium Trust. He was succeeded as president of the Court of Appeal by
Christine French on 21 November 2024. In the
2025 King’s Birthday Honours, Cooper was appointed a
Knight Companion of the New Zealand Order of Merit, for services to the judiciary. ==See also==