Many Australians were exposed to false and harmful claims about the science of COVID-19. Understanding who shares this misinformation with other people and finding the underlying reasons for it has become a pressing interest to researchers and professional science communicators alike. However, researchers have conflicting views on which factors are the most important. Much of this debate has occurred outside the Australian cultural context, is confined to understanding the sharing of misinformation only within social media communication channels, or focuses on topics other than infectious diseases, where understanding and mitigating misinformation-sharing behaviour is becoming increasingly important. These gaps present challenges for Australia’s professional science communicators, who may seek this knowledge to develop communication strategies that discourage the sharing of harmful misinformation about infectious diseases. Therefore this project aims to statistically predict which Australians were likely to share already-debunked misinformation about COVID-19 based on a wide range of individual-level cognitive, psychological, and socio-demographic factors and extend this approach to define and segment priority audiences to inform well-targeted communication strategies. Consequently, it aims to provide recommendations to public health authorities to inform Australia’s future emergency management responses.