This study examined the extent to which elementary teachers implement differentiated instruction (DI) and their level of competence in applying its principles in Cluster 1 of the Division of Negros Occidental during the Academic Year 2025–2026. Using a mixed-method research design, the study involved Grades 4–6 teachers, school heads, and Education Program Supervisors as respondents, utilizing survey questionnaires and semi-structured interviews to gather data. Quantitative data were analyzed using mean and standard deviation, while qualitative data were thematically analyzed to explore teachers’ lived experiences, challenges, and support needs. Findings revealed a high level of DI implementation (M = 4.87) and above-average teacher competence (M = 5.09), indicating that differentiated strategies such as problem-solving, experiential learning, collaborative activities, and interactive approaches are frequently applied in elementary classrooms. Teachers demonstrated strengths in managing classroom routines, modifying instructional materials, and integrating innovative strategies such as games, dramatization, and ICT; however, areas for improvement were noted in designing tiered activities and providing varied formats for student outputs. The findings further showed that DI enhances student engagement, academic performance, confidence, and collaboration, although challenges such as large class sizes, limited preparation time, insufficient resources, and rigid curriculum requirements hinder its consistent implementation. Teacher motivation, supported by both intrinsic factors and administrative assistance, was found to sustain the use of DI practices. Based on the integrated findings, an intervention program was proposed to strengthen teachers’ capacity in differentiated instruction. This study contributes to the field of education by providing empirical evidence and practical insights that support the development of inclusive, learner-centered, and responsive teaching practices in diverse elementary classroom settings.