Citizens are now central to national security strategies, yet governments readily admit that little is known about public opinion on security. This article presents a unique and timely examination of public perceptions of security threats. By focusing on the breadth of security threats that citizens identify, their psychological origins, how they vary from personal to global levels, and the relationships between perceptions of threats and other political attitudes and behaviours, the article makes several new contributions to the literature. These include extending the levels at which threats are perceived from the national versus personal dichotomy to a continuum spanning the individual, family, community, nation and globe, and showing the extent to which perceptions of threat at each level have different causes, as well as different effects on political attitudes and behaviour. These findings are also relevant to policy communities’ understanding of what it means for a public to feel secure.