Academic achievement and in-classroom behaviors are two significant child outcomes that affect student success in school. According to Systems Theory, in order to truly understand the factors that affect these outcomes for children, one must look to the major systems that encapsulate the child (including their school and home environments). This project is a meta-analytic review that examined the effectiveness of measures representing each system in predicting child achievement and behavior: School-Wide Positive Behavior Supports (SWPBS) for the school as a system, level of parent involvement (high versus low) for the home system, and student motivation (intrinsic versus extrinsic) for the child system. Archival research was used to examine children who attended K-12 schools in various Westernized countries. A total of 15 studies were examined to compute the effect sizes which were combined to examine the relative strength of each factor on the two outcome variables. For academic achievement, it was found that effect sizes were very large for SWPBS (0.768) and student motivation (0.807), and were large (0.589) for parent involvement. For behavior, SWPBS was associated with a very large effect size (-0.780). In other words, SWPBS is strongly associated with both increased academic achievement and decreased problem behavior, whereas parent involvement and student motivation are strongly associated with increased academic achievement. A suggested systems approach including the school counselor is proposed that meshes the effects of these three child systems into a more fluid, collaborative model that address child academic achievement and behavioral concerns.