This explanatory sequential mixed-methods study explored the role of cognitive and noncognitive constructs, namely volitional competence, grit and metacognitive awareness in the academic achievement among online higher education learners in the Philippines. The first phase of the study involved the administration of the survey to 403 learners. Data from individual interviews and focus-group discussions were used in the second phase to illuminate further the initial quantitative results. The findings show that volitional competence, grit, and metacognitive awareness are significant predictors of academic achievement of online learners based on the generated regression model [F (3,313) = 8.4, p < 0.001, R[superscript 2] = 0.475]. Also, both the quantitative and qualitative data reveal areas for improvement such as learners' lack of confidence to succeed in their academic tasks online and uncontrollable distractions at home for volitional competence, sustaining their interest and focus for grit, and awareness about what constitutes relevant knowledge with respect to certain tasks, assessment of their thinking, and simplification of complex tasks to manageable forms for metacognitive awareness. Implications of these findings necessitate schools to streamline their curricula, revisit learning activities provided to online learners, and form a stronger linkage between parents and teachers to empower online learners and improve their academic achievement.