Whetumarama Wereta (Whetu Wereta, née Rolleston) is a Māori political scientist and statistician from Lower Hutt, New Zealand. She belongs to the Ngāi Te Rangi and Ngāti Ranginui iwis. Wereta has served as the Mäori representative on several government commissions or committees on the electoral system, education and justice.
Wereta gained a BA Hons degree, then joined the Department of Statistics in the early 1970s. In 1992, Wereta became manager, Maori Statistics. She has also worked as a policy researcher and/or a manager in the Ministry of Maori Development and its predecessors, and in the Department of Internal Affairs. Wereta was employed as a social researcher at the Department of Maori Affairs in Wellington in 1988. Wereta served on the New Zealand National Commission for UNESCO. She was one of the three members of the Local Government Commission from 1 April 1990 until 31 March 1993, along with Sir Brian Elwood and Doug Pearson. Rejoining Statistics New Zealand in 2001, she was appointed General Manager, Maori Statistics.
Wereta was a member of the five-person 1985-86 New Zealand Royal Commission on the Electoral System that recommended mixed member proportional representation (MMP) for elections to the New Zealand Parliament, a major change from the previous first-past-the-post system. She was the only member of the commission with a known political affiliation (to the Labour Party), and also the only Maori and the only woman on the commission. The committee embraced the principles of fairness to women and to the Maori in their report, which was accepted. New Zealand now follows an MMP system of elections.