This study examined the causes of low reading proficiency levels in English among Grade 7 students of Sulat National High School during the School Year 2024–2025. Using a descriptive-correlational research design, the study involved 155 Grade 7 students and 10 English teachers as respondents. Data were collected through a standardized reading proficiency test adapted from the Philippine Informal Reading Inventory (Phil-IRI) and a researcher-made survey questionnaire that measured home-related, student-related, teacher-related, and school-related factors affecting reading proficiency. Findings revealed that the majority of the students were classified at the Developing and Approaching Proficiency levels, with a mean proficiency score of 2.41, indicating generally low reading performance in English. Home-related factors such as limited parental support, inadequate availability of reading materials, and minimal exposure to English at home were found to significantly contribute to low reading proficiency. Student-related factors, including motivation, study habits, reading confidence, and attitudes toward reading, showed the strongest relationship with reading performance. Teacher-related factors demonstrated a moderate influence, reflecting adequate teacher competence but limited implementation of differentiated reading interventions. School-related factors, such as insufficient reading programs, limited library resources, and large class sizes, also contributed to students’ reading difficulties. Pearson Product-Moment Correlation analysis revealed that all identified factors—home-related, student-related, teacher-related, and school-related—had significant relationships with students’ reading proficiency levels, with student-related factors exhibiting the strongest correlation. The study concludes that low reading proficiency among Grade 7 students is a multifaceted issue resulting from the interaction of individual, instructional, home, and institutional factors. It recommends a holistic and collaborative approach involving students, parents, teachers, school administrators, and policymakers to strengthen reading instruction, enhance home literacy environments, and improve school-based reading programs.