Domestic theories of democratization emphasize the role of values, interests, and mobilization/opportunities as determinants of regime change. This article takes a step back and develops a model of national personality and democratization to ascertain the indirect effect of national personality traits on worldwide variation of regime type. In particular, I theorize that personality traits influence a country’s regime type by shaping citizens’ traditional and self-expression values, which, in turn, influence the establishment and consolidation of democratic institutions. Data from McCrae and Terracciano’s assessment of the five-factor model from 47 countries allow me to assess this hypothesis empirically. Results reveal that countries whose societies are high in Openness to experience tend to have more democratic institutions, even after adjusting for relevant confounders: economic inequalities, economic development, technological advancement, disease stress, climate demands, and methodological characteristics of the national sample. Although the effect of Extraversion on a country’s democratic institutions is also significantly positive, the inclusion of confounders weakens the reliability of this association. In an exploration of the mechanisms of these associations, a mediation analysis shows that the relationship between national Openness and democratic institutions is channeled through secular and especially self-expression national values. The same analysis with the effect of Extraversion on democracy indicates that the association between this trait and democracy is only channeled through national self-expression values but not national secular values. In short, this article constitutes a first step toward a more complete understanding of the cross-cultural psychological roots of political institutions.