Abstract: Effective learning relies heavily on student engagement. It reflects how involved and motivated students are in their studies, which directly influences their learning outcomes and personal development. This quantitative study determined the best-fitting structural model of the endogenous variable – student engagement – as influenced by four exogenous variables: classroom management, classroom environment, students’ school motivation, and learning behavior among public senior high school learners in Region XI. A non-experimental, descriptive-correlational design with structural equation modeling (SEM) was employed, involving 400 senior high school learners from 11 school divisions selected through systematic stratified sampling. Descriptive analysis revealed high levels across all exogenous variables, while student engagement—measured in affective, behavioral, and cognitive domains—was found to be very high. Correlation analyses indicated significant relationships between student engagement and the four exogenous variables. Further, the findings identified Model 3 as the best-fitting model, signifying direct causal relationships between the four exogenous variables and student engagement. After model modifications, classroom management was best described by effective factors and teachers’ strategies. Classroom environment was represented by its two indicators: proper ventilation of classroom and seats and sitting arrangement. Likewise, students’ school motivation was measured by its two indicators: self- determination and career motivation. Additionally, learning behavior was described by its two remaining indicators: responsibility and motivation. Student engagement was most measured by its indicators- affective; liking for school and behavior; effort and persist. These findings have meaningful implications for educators and policymakers in designing targeted interventions that enhance learner participation, motivation, and achievement in senior high schools. Keywords: student engagement, classroom management, learning environment, student motivation, learning behavior, SEM, Region XI. Title: Classroom Management, Classroom Environment, Students’ School Motivation, and Learning Behavior: A Structural Equation Model on Student Engagement of Public Senior High Schools Author: Pedro R. Sulatre, Jr., Eugenio S. Guhao, Jr. International Journal of Novel Research in Education and Learning ISSN 2394-9686 Vol. 13, Issue 1, January 2026 - February 2026 Page No: 47-68 Novelty Journals Website: www.noveltyjournals.com Published Date: 26-February-2026 DOI: https://doi.org/10.5281/zenodo.18788575 Paper Download Link (Source) https://www.noveltyjournals.com/upload/paper/Classroom%20Management,%20Classroom%20Environment-26022026-5.pdf