Developing legislative interventions to address firearm misuse is an issue of considerable public policy interest across many countries. However, systematic reviews of evidence about the efficacy of legislative change in reducing lethal firearm violence have only considered research examining the United States of America, a country that is unique among developed nations in its approach to firearm ownership. To inform international policy development, there is a need to consider other countries' experiences with gun law amendments. The current study used systematic literature search methods to identify evaluation-focused studies examining the impacts of legislative reform on firearm homicide in Australia, a country that made significant changes to its gun laws in the mid-1990s. Five studies met the inclusion criteria. These examined various different time periods, and used a range of different statistical analysis methods. No study found statistical evidence of any significant impact of the legislative changes on firearm homicide rates. The strengths and limitations of each study are discussed. Findings from this review provide insights into strategies and policies that may, and may not, be effective for reducing lethal firearm violence.