This study is a meta-analytical examination of the relationships between academic achievement, motivation, and self-directed learning. It aims to review scientific studies investigating how self-directed learning readiness relates to both motivation and academic achievement to find a common effect level and to synthesize the study results. According to the meta-analytical results, it can be seen that academic achievement increases in line with an increase in the level of self-directed learning readiness. The results reveal that the relationship between self-directed learning and both motivation and academic achievement, which are two important indicators of the educational process, constitutes an important structure. It is recommended that relational studies conducted at the K-12 level of the relationship between self-directed learning and motivation should be compared with the results of this study through a separate meta-analysis.