This research aims to examine the influence of self-confidence on students' mathematical critical thinking abilities. The study involved 27 students from class VIII A at SMPN 4 Bandar Lampung. The method employed in this research was a quantitative approach using data analysis techniques such as regression analysis and characterized as an ex-post facto study. The research instruments included a test of critical thinking abilities consisting of 8 items that underwent processes of validity testing, reliability testing, difficulty level assessment, and discriminant power testing. Additionally, there was a student perception questionnaire regarding teacher performance consisting of 25 statement scales adopted from Febriandari Siwi (2021) with indicators: a) Confidence in one's abilities; b) Independence, responsibility, and desire for high achievement; c) Persistence; d) Willingness to take action. The findings of this study indicate that self-confidence does not have a significant influence on students' mathematical critical thinking abilities. There might be other factors, such as family support, learning motivation, or teaching methods, which were not encompassed in this research. Each student responds uniquely to mathematical challenges, hence the impact of teacher performance may vary among individuals and necessitates further consideration. The results suggest that factors beyond self-confidence play a crucial role in developing students' mathematical critical thinking skills. Educators and researchers can further explore these factors for a more comprehensive understanding, considering the relevance of outcomes within specific learning contexts and student characteristics. Despite the absence of a detected significant influence, practical implications include efforts to enhance other factors supporting students' mathematical abilities, such as developing additional teaching strategies or improving family support and environmental factors outside the classroom