Risk perception is the subjective evaluation of potential hazards, which is influenced by cognitive biases, emotive responses, social influences, and cultural factors. Although security professionals depend on data-driven risk analysis, individuals frequently interpret risks using heuristics, such as optimism bias or availability bias, which can result in inaccurate assessments. Public perceptions are further amplified or distorted by media narratives and digital platforms, which in turn influence collective risk behaviours. This chapter investigates the psychological and social mechanisms that underlie risk perception, emphasising the influence of personal experiences, demographic factors, and societal norms on security-related decision-making practices. In order to improve security preparedness, it is essential to comprehend these dynamics in order to develop effective risk communication strategies and align public perceptions with actual risks.