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<div> This article presents the development and validation of the Short <i>Phronesis</i> Measure (SPM), a novel tool to assess Aristotelian <i>phronesis</i> (practical wisdom). Across three studies, using large, nationally representative samples from the UK and US (demographically matched to census data), we employed a systematic and rigorous methodology to examine the structure, reliability, and validity of the SPM. In Study 1a, exploratory factor analysis identified ten distinct, internally reliable components of <i>phronesis</i>, challenging the traditional four-component Aristotelian model. Study 1b confirmed these findings in two additional nationally representative samples from the UK and the US. In Study 1c, the SPM demonstrated strong test-retest reliability over two months. Study 2 used network analysis to uncover interrelations among the components, allowing for the creation of a new and empirically driven <i>neo</i>-Aristotelian model of <i>phronesis</i>. In Study 3, we tested criterion validity, showing <i>phronesis</i> correlates positively with flourishing and predicts flourishing two months later, demonstrating strong predictive validity. <i>Phronesis</i> also correlated with Big 6 and Dark Tetrad personality traits, moral disengagement, and Moral Foundations in expected directions. Importantly, <i>phronesis</i> predicted key outcomes—related to flourishing, moral disengagement, and morally relevant aspects of personality—beyond what Moral Foundations alone explained, with an average increase in predictive power of 13.7% across all outcomes. The SPM is quick to administer (15–20 minutes), making it a valuable tool for researchers and practitioners in psychology, education, and professional ethics. The introduction of the neo-Aristotelian <i>Phronesis</i> Model, and the identification of central <i>phronesis</i> components, offers actionable insights for moral psychologists and moral educators, suggesting areas of focus that could yield broad, positive effects across related traits, providing a significant contribution to both theory and practice. </div>