Populism, an academically contested political theory, has been subject to few thorough studies in the New Zealand context. With a history of strong, successful leaders, and fervent political rebels, New Zealand provides a useful political context in which the theoretical platform for what constitutes populism can be explored. While the current pre-eminent model of New Zealand-centric populist leadership is Barry Gustafson’s six point framework, this thesis will posit that adopting a multi-methodological approach is able to explain the nuances of New Zealand populism more effectively. Traditional international approaches to populist theory, such as those of Panizza and Laclau, are introduced to provide context on the wider literature on populism. In a challenge to Gustafson’s model, which closely matches the definitions of Panizza and Laclau, the social choice theorems of Riker’s heresthetics are introduced to provide a counter-explanation for populist leadership. The study applies the theories of traditional populism and heresthetics to three case studies of New Zealand leaders; John A. Lee, Winston Peters, and Richard Seddon. Through application of Gustafson’s model to these leaders, we see that his criteria are only significantly met in the cases of Lee and Peters, while the criteria are only partially met in the case of Seddon. In regards to Seddon, Riker’s heresthetics and the theorems of Panizza and Laclau equally explain his populism. After classifying the populism of each case study, an attempt is made to explain why each selected leader was drawn to a particular style of populism, and it is posited that Renshon’s construct of relatedness, a dimension of his over-arching theory of character, can provide a qualitative answer to this question. These case studies demonstrate that populist leadership in New Zealand needs to be seen as a continuum, in which populist leaders vary in the degree to which they fit within particular theoretical classifications, and that a multi-methodological approach is necessary to explain the nuances of each case. The study posits that this approach will aid further study, particularly when analysing modern leaders that employ a milder variant of populism.