Learners' individual differences in mathematics achievement are associated with individual differences in psychological characteristics. A number of meta-analyses have quantified the strengths of these correlations. However, these findings are scattered across different strands of the literature. The present systematic review aims to integrate these strands by providing an overview of meta-analyses of psychological correlates of mathematics achievement. We conducted a systematic literature search and included 30 meta-analyses, reporting correlations between mathematics achievement and 66 variables based on 13,853 effect sizes and an estimated 4,658,717 participants. The correlations are rank-ordered by size and complemented with information about the meta-analyses, their inclusion criteria, and methods. The results show strong associations of mathematics achievement with verbal skills and abilities, prior knowledge, intelligence, creativity, math-specific skills, math self-concept, self-regulation, meta-cognition, and executive functions. Relatively weaker relations were observed for emotional intelligence, achievement goals, academic emotions, and the Big Five personality traits.