Other than cognitive ability, what competencies should schools promote in children? How are they organized, and to what extent do they predict consequential outcomes? Separate theoretical traditions have suggested interpersonal, intrapersonal, and intellectual dimensions, reflecting how children relate to other people, manage their own goals and impulses, and engage with ideas, respectively. However, very little work has examined character empirically. In the current investigation, we partnered with middle schools that had previously identified character strengths relevant in their communities. Across three longitudinal, prospective studies, we examined the factor structure of character, associations with intelligence and Big Five personality traits, and predictive validity for consequential outcomes like peer relations, class participation, and report card grades. In Study 1, teachers rated their students on behaviors exemplifying character strengths as they played out in students’ daily lives. Exploratory factor analyses yielded a three-factor structure consisting of interpersonal (interpersonal self-control, gratitude, social intelligence), intellectual (zest, curiosity), and intrapersonal (academic self-control, grit) factors of character. In Study 2, children rated their own behavior and completed a test of cognitive ability. Confirmatory factor analyses supported the same three-factor structure, and these factors were only weakly associated with cognitive ability. In Study 3, teachers provided character ratings; in parallel, students completed measures of character as well as Big Five personality factors. As expected, intellectual, interpersonal, and intrapersonal character factors related to Big Five openness to experience, agreeableness, and conscientiousness, respectively. Across studies, positive peer relations were most consistently predicted by interpersonal character, class participation by intellectual character, and report card grades by intrapersonal character. Collectively, our findings support a tripartite taxonomy of character in the school context.