Poor student classroom engagement is worsening. This study aimed to determine the significance of teachers' instructional competence and adaptability skills as predictors of students’ classroom engagement. Utilizing a descriptive correlational design and involving 326 Humanities and Social Sciences students, the results indicate that the predictive variables positively influenced the criterion variable, affirming the social cognitive theory. Other variables not covered in the study may be explored to ascertain the 34.5 percent variance in students’ classroom engagement. Further studies in line with the interest of Sustainable Development Goal (SGD) 4 are also recommended.