This meta-analysis provides the first comprehensive synthesis of associations between student and teacher personality traits and the quality of teacher-student relationships. Fifty-five studies met the eligibility criteria, contributing a total of 238 effect sizes. We used multivariate meta-analysis with robust variance estimation (RVE) to model the dependency of effect sizes. Student prosocial behavior (ρ = 0.59) and proactive personality (ρ = 0.48) were the strongest predictors of positive teacher-student relationship quality. All Big Five traits of students, except neuroticism, showed significant positive associations, with all correlations exceeding 0.4 when holding constant with all other moderators. Teacher agreeableness (ρ = 0.31) and conscientiousness (ρ = 0.29) yielded modest associations. Students with less emotional stability or aggressive behaviors were more likely to experience negative teacher-student relationships, such as conflict and dependency. Our findings highlight the critical role of student personality in explaining the quality of teacher-student interactions. Multiple traits appear equally important, as indicated by comparable effect sizes. The literature is relatively limited when it comes to teacher personality. We were unable to examine teacher traits in relation to teacher-student conflict and dependency, but, overall, agreeable and conscientious teacher behaviors appeared to be important for favorable interactions, whereas teacher neuroticism may undermine the quality of such interactions.