Research on self-concept and mathematics learning achievement has been done a lot, both at the elementary, junior high, high school and university levels. The average research shows a relationship between self-concept and mathematics learning achievement, so it is necessary to conduct a meta-analysis of correlational studies. Data were obtained from national journals and international databases with predetermined criteria. Based on the search, 28 studies met the specified criteria. Data analysis used a random effects approach. The software used in the analysis is JASP. 0.8. 4.0. The results of the analysis show the Q value with p-value <0,05; τ² or τ> 0; and I² (%) close to 100% of the sample used meets the assumption of heterogeneity. Kendal Value τ with p-value> 0,05; and Z value with p-value> 0,05, and the image generated by the random effects model with the results of the analysis using the trim-fill approach is not different, it can be concluded that there is no publication bias. The results of the analysis show that there is a positive and significant relationship between self-concept and mathematics learning achievement. The resulting summary effect size was 0,62 in the medium category. Summary effect size values are in the interval 0,49 to 0,75. The results of this study indicate consistency and support for the theory of self-concept development.