Schoolies is the largest youth mass gathering in Australia. An estimated 36% of Australian school leavers participate in some kind of Schoolies event each year, involving approximately 60,000 young people aged 17 and 18, who gather at locations around Australia to celebrate the end of secondary school. However, Schoolies involves significant risks to the safety of the local community and property as well as to attendees. This project is a five-year partnership between researchers and the Queensland Government Department of Child Safety, Youth and Women that aims to investigate how group processes affect safety at mass gatherings. This is significant because previous mass gatherings research has focused on top-down strategies to improve service delivery, but has rarely considered the crowd psychology of people attending such events. This project seeks to work with, rather than against, the psychology of crowds, in order to (1) develop a new interdisciplinary model of how intra and intergroup processes affect risk taking, trust and safety, and (2) an evidence base to improve help seeking and reduce risk taking at the largest youth mass gathering in Australia. This is expected to provide dual benefits of advancing fundamental science and delivering practical solutions for our partners in government, police, health and the community.