The present study examined whether there were differences in school maladjustment and academic achievement depending on the level of grit (Duckworth et al., 2007) and self-control. Grit was measured by two sub-factors such as persistence of effort and consistency of interest. A total of 535 college students of Open University was recruited. First, Latent Class Analysis (LCA) was employed to investigate whether there exist distinct but unobserved groups among subjects in terms of the level of grit and self-control. The results showed that three qualitatively different groups were identified: high, middle, and low groups. Students who demonstrated high grit and self-control were less likely to show school maladjustment, measured by academic, emotional, and career-related problems. The differences of academic achievement across three groups, however, were not statistically significant. Second, we investigated whether personality significantly predicted latent class memberships. Results of multinominal logistic regression displayed that neuroticism and conscientiousness significantly predicted high, middle, and low groups of grit and self-control. That is, when the level of neuroticism increases, the probability of being in the higher group decreased; when the level of conscientiousness increases, the probability of being in the higher group increased. Theoretical and practical implications were discussed.