Achievement in statistics and probability mathematics is one of the issues that many senior high school learners are facing, and thus there is a need to investigate the factors that affect learning, not only cognitive but also non-cognitive. This study sought to determine the effect of mathematics grit on performance in mathematics among Grade 11 learners enrolled in public senior high schools in Cordon, Isabela for the second semester in School Year 2025-2026. This study used theories such as Grit Theory, Social Cognitive Theory, and Growth Mindset Theory. The research design used was quantitative correlation design involving 196 respondents sampled using stratified systematic sampling. The findings showed that the students exhibited very high mathematics grit levels in all the domains, but in terms of performance, the proficiency level was low. Differences in selected domains of grit were also found among the groupings based on sex and academic strands. According to the results obtained from the Pearson correlation test, there is a significant but weak positive correlation between mathematics grit and performance. The finding implies that even though perseverance plays an important role in engagement, it is not enough in achieving high performance on its own.