Suicide remains one of the leading causes of death in young people and contributes significant social, economic and health system costs to Australia. The rate of suicide has remained constant in the Australian population despite substantial government and private investment, significant community and political momentum, and efforts to improve coordination and alignment of programs and services. Dynamic simulation modelling is increasingly being recognised as a valuable decision support tool to help guide investments and actions to address complex public health problems such as suicide. In particular, system dynamics (SD) modelling provides a useful tool for asking high level ‘what if’ questions; testing at an aggregate level the likely impacts of different combinations of policies and interventions before they are implemented in the real world. This paper reports the development of an SD model of suicide prevention in Australia and its findings. Additionally, the paper highlights the value of dynamic modelling methods for managing complexity and uncertainty and demonstrates its potential utility as a decision support tool for policy makers and program planners for suicide prevention.