Variance in how citizens interact with the political world constitutes one of many classes of individual difference. Understanding the antecedents of this variance is the central objective for students of political behaviour, and researchers draw on numerous factors in addressing this task. Unfortunately, one potentially vital factor, personality, has received only sporadic attention in recent decades. Neglect of personality was understandable for many years, as psychological research on personality failed to produce concise taxonomies applicable to the study of politics. As the present analysis demonstrates, however, this situation has changed. Research on personality has gained new footing with the emergence of a series of five-factor models, and these frameworks hold great potential for the study of political behaviour. This thesis is advanced in a two-part analysis. First, we outline how and why our understanding of citizen politics may be improved through application of five-factor models of personality. In doing so, we focus on the components of one specific taxonomy, the Big Five lexical model. Secondly, using three datasets, we explore the link between the Big Five personality factors and a wide array of political attitudes and behaviours. Results reveal that all facets of personality captured by the Big Five framework matter for citizen politics, and that personality effects operate on virtually all aspects of political behaviour. These findings demonstrate the insight that can emerge with further application of broad-scale models of personality