The study investigates how mathematics self-efficacy and reading comprehension proficiency affect mathematics proficiency among grade 10 students in private schools of Maniki. A quantitative, descriptive-correlational design was used, with 183 randomly selected students surveyed on the three variables. The results indicated that students had high levels of mathematics self-efficacy, reading comprehension proficiency, and mathematics proficiency. It was found that a significant relationship exists between mathematics self-efficacy and mathematics proficiency, while no significant relationship was observed between reading comprehension proficiency and mathematics proficiency. Additionally, the domains of mathematics self-efficacy, including mastery experiences, vicarious experiences, verbal persuasion, and psychological states, were found to significantly influence students' mathematics proficiency. However, the domains of reading comprehension proficiency—literal comprehension, inferential understanding, and creative understanding—did not significantly impact mathematics proficiency. These findings suggest that mathematics self-efficacy plays a significant role in enhancing mathematics proficiency among grade 10 students.