There is strong support for a combination of evidence-based strategies to address a complex public health concern such as suicide. Complex, multilevel, and multicomponent interventions can be effective in addressing this concern. However, little is known about the processes involved in the adoption, delivery, and sustainment of these interventions. While efficacy and effectiveness studies have contributed to an evidence base around what works to prevent suicides, little is known regarding how to translate these findings into feasible, acceptable, and cost-effective programs, applicable across real-life settings. This study aimed to – a) contribute to a better understanding of the processes involved in the adoption, delivery, and sustainment of complex suicide prevention interventions; b) contribute toward development of best practice guidelines for implementation. The objective was to coalesce the field to develop a shared understanding on how best to utilise principles of implementation science to advance our understanding of what works, for whom, why and in what contexts – for suicide prevention. The objective was achieved through three studies. Firstly, a systematic literature review was conducted to understand the extent to which implementation science is utilised in complex suicide prevention interventions. Secondly, a qualitative study was conducted with stakeholders (leaders, implementation practitioners/project managers, and lived experience advocates) involved in implementation of complex suicide prevention interventions. Semi-structured interviews helped to understand their experiences on the ground – mechanisms of change; barriers and facilitators; challenges; lessons learned and the way forward in suicide prevention. Thirdly, an online Delphi consultation was conducted with diverse stakeholders (leaders, project managers, lived experience advocates, research experts) within suicide research and prevention across 27 countries. Participants were encouraged to deliberate on strategies to harness implementation science for suicide prevention across three rounds. A set of 82 statements across six areas of consideration were endorsed as potential strategies for utilising implementation science for suicide prevention efforts. These recommendations offer practical guidance on how to effectively apply implementation science to suicide prevention. Future efforts need to prioritise finalising the guidelines, evaluating their feasibility, and developing clear strategies to implement them in real-world settings.