This meta-analysis examined whether motivation mediated the relationship between self-efficacy, locus of control, and academic achievement. Thirty-seven studies providing correlation estimates for 40 different samples were included in the analysis. The data from these studies were fitted to three models using a two-stage structural equation modelling method. In stage 1, a total correlation matrix was created by combining the correlations. In stage 2, this matrix was used for examining the models. First, a proposed model was fitted to examine the effect of self-efficacy and locus of control on achievement through motivation. Second, an alternative model was tested by drawing a direct line from self-efficacy to achievement. Third, another model was tested by examining the mediating role of motivation between self-efficacy and achievement. The analyses suggested that academic achievement significantly correlates with self-efficacy (r=0.218) and motivation (r=0.237). Motivation significantly correlates with self-efficacy (r=0.415) and locus of control (r=0.216). However, locus of control does not correlate with self-efficacy and achievement (p>0.05). Self-efficacy and locus of control positively influence motivation. Self-efficacy influences achievement both directly and indirectly through motivation. The findings provide a general overview of how these variables correlate and affect student achievement.