Background This thesis considers the implications implementation science has for Indigenous communities, specifically in reducing health inequities for the Māori community of New Zealand. Implementation science has been discussed among many Western health interventions and this thesis adds to that body of literature while highlighting the impact implementation has for Indigenous communities. Implementation science is a growing body of literature that can identify the most effective processes for health organisations and governments to best engage with Indigenous communities facing health inequities. An important aspect of that is ensuring the Indigenous voices and perspectives are represented just as much as the academics and scholars in those fields. The purpose of this thesis is to highlight the facilitators and barriers of implementing health interventions with Māori communities in Aotearoa New Zealand. This thesis aims to contribute to the conversation about reducing health inequities Māori communities’ face in New Zealand by enhancing implementation effectiveness. Therefore, it is an effort to illuminate the importance of the inclusion of community voice and perspectives when implementing health interventions with Indigenous communities. The thesis is with publications and includes four distinct studies. Methodology & Methods The key methodologies used in this study were Kaupapa Māori methodology and the He Pikinga Waiora (HPW) Implementation framework. Kaupapa Māori has been used as both a form of resistance and a methodological strategy, where research is created, developed, and carried within a Māori worldview with the aim to have positive outcomes that are beneficial for Māori. The HPW framework provided a holistic approach to guide this research through its key elements of: culture-centered approach, community engagement, systems thinking, and integrated knowledge translation. It is a forward-thinking approach as it is flexible in its design, which allows the framework to be tailored to a variety of implementation situations. The framework is centred in Kaupapa Māori methodology. Each principle of Kaupapa Māori and each element of HPW provide a holistic approach to implementation science. Given this thesis includes four publications, a range of methods were employed for data collection. The first study was a systematic review of studies that was completed using preferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines. This involved a stringent search strategy and inclusion criteria where studies included went through data extraction and methodological appraisal followed by an analysis through a qualitative synthesis of findings. Studies two and three employed semi-structured interviews that were analysed through thematic analysis. Study two included 19 participants who were either health professionals or researchers, and study three included 17 participants who were health professionals. The fourth study included an online cross-sectional survey of 200 health professionals and used statistical modelling to identify factors important for implementation effectiveness. Results The first study included a systematic literature review to examine the implementation of a non-communicable disease health intervention for Indigenous communities using HPW as an evaluation tool. Twenty-one studies were included. Two thirds of these studies demonstrated high levels of community engagement and community voice/ agency, while 40% had individual-level outcomes with some systems thinking, and 33% included individual-level outcomes and limited systems thinking. Finally, almost 40% of studies included high levels of end-user engagement reflective of integrated knowledge translation, but nearly half had limited end-user engagement with the remaining neither high or low. This study found that the HPW Implementation Framework is a comprehensive model for understanding implementation effectiveness in Indigenous communities and highlighted the high levels of community engagement and community voice. It also brings to light that the long-term sustainability and translation of evidence to practice may be inhibited because of lower levels of systems thinking and integrated knowledge translation. The second study researched the perceptions health professionals have on co-designing health-promotion interventions with Indigenous communities in New Zealand. Co-designing health-promotion interventions with Indigenous communities presents many benefits and challenges. This study identified that the facilitators for co-designing health-promotion interventions with Māori communities were collaboration and community voice. Furthermore, the two key barriers identified were mismanaged expectations between the researcher and community and the research constraints placed by funding agencies. The findings support the development of more effective co-design health-promotion interventions within Māori communities which may address health inequities. The third study endeavoured to identify the facilitators and barriers in disseminating and adopting a health intervention developed by a community-academic partnership. This study explored general perceptions of the implementation process and also included a case study of an innovative intervention. The facilitators included community engagement, programme structure, programme adaptability and creators’ experience. The barriers consisted of funding access, funding constraints and organisational constraints. This study also highlights the importance of community engagement and adaptability suggesting a need for translation as well as diffusion. Additionally, this study identified nuanced aspects of funding and resources for organisations that constrain organisations in employing health interventions designed by others. The final study identified factors that New Zealand health professionals rate as important for implementation effectiveness for health interventions with Māori communities. This study provided a unique perspective of health professionals on implementation effectiveness when working with Māori/Indigenous communities. Paired sample t-tests revealed four levels of importance for implementation effectiveness with organisational teamwork and community autonomy as most important. Only 24% of participants had prior experience with a previous health intervention with Māori communities. The two key overall factors that were associated with participants’ rating of implementation effectiveness in these previous interventions were process and community. This study identified the key areas of implementation effectiveness as community engagement and participatory process. Furthermore, the final study contributes to the body of literature that challenges traditional top-down approaches of implementation. Conclusion This research aimed to identify the facilitators and barriers to disseminating and implementing health interventions with Māori communities in New Zealand. A synthesis of the four studies provided four key themes for this thesis. This thesis reinforces the position that Indigenous and Māori implementation science should be focused on the process and community engagement. In doing so, community engagement ensures a cultural-centred approach that prioritises Indigenous knowledge and autonomy in the process of implementation. Furthermore, the barriers identified in this thesis recognise the challenges that remain in limited funding for translating research into implementation practice and managing expectations amongst the implementation team. This thesis has implications for New Zealand district health boards and health organisations who are wanting to increase the effectiveness of the health interventions they are implementing with Māori communities, particularly when trying to address health inequities. Overall, this study is an attempt to bridge the gap between translating research and the processes of putting it into practice.