This study conducted a latent class analysis of Taiwanese students’ proactive mathematics learning behaviors in the Programme for International Student Assessment 2022 to explore potential classifications and examine the relationships between different categories of proactive mathematics learning behaviors, gender, and mathematics performance and their moderating effects on gender differences in mathematics literacy. The proactive mathematics learning behaviors of Taiwanese middle school students can be divided into five latent categories, with gender influencing these categories. Notably, a large proportion of female students were observed in the "passive and not persistent" and "focused but passive" categories. The "proactive and persistent" category demonstrated the highest levels of mathematics literacy, and the "proactive but not persistent" and "passive but persistent" categories demonstrated the lowest levels. Gender differences in overall mathematics literacy were minimal. Girls scored slightly higher than boys in the "proactive but not persistent" category. Conversely, boys outperformed girls in the other four categories, with boys in the "focused but passive" category scoring 36 points higher. In the remaining categories, boys scored significantly higher than did girls, although the difference was not significant. Overall, this study offers valuable teaching and research suggestions.