This study aims to determine the correlational effect sizes between teacher relationships and student academic achievement. Teacher relationships were categorized as intrapersonal and interpersonal relationship types. Intrapersonal and interpersonal relationships are directed at different individuals. Intrapersonal relations refer to the inner life and thoughts of a teacher which are effective on the way of teaching and human relations. Interpersonal relations refer to social links between a teacher and the other people of the school community. The method of the study is second order meta-analysis. In this method, effect sizes of the first order meta-analyses are combined to get an average effect size score. Totally, 17 eligible first order meta-analyses are included in the study. The findings indicate that the correlational effect size between a positive teacher intrapersonal relationship and student academic achievement is positively small, positive teacher student relationship and student academic achievement is positively medium, a positive teacher school community relationship and student academic achievement is positively at a very large level. Also, correlational effect size representing a negative teacher intrapersonal relationship and student academic achievement is negatively medium, a negative teacher student relationship and student academic achievement is negatively small. As for moderator analyses, the variance of the effect sizes is statistically significant according to the positive relationship types and the publication types. In light of the findings some suggestions were made to improve teacher and school community relations that may help teachers and students to be more successful.