This study attempted to determine the correlation between school principals’ instructional supervision and teachers’ efficacy in public elementary schools in Baliwasan District, Zamboanga City, Philippines. The survey questionnaires were used to gather data on school principals’ instructional supervision and teachers’ efficacy. Weighted Mean, Pearson product-moment correlation coefficient, and one-way analysis of variance were used in the analysis of data. The findings indicated that the elementary school teachers in Baliwasan District are bachelor’s degree holders with/ Master’s units and a few of them are holders of Master’s Degree, Master’s Degree with doctorate units, and doctorate holders. The teachers manifested a great extent of their teaching efficacy in student engagement, instructional strategies, and classroom management. The instructional supervision of the principal is related to the teaching efficacy of the teachers in terms of student engagement, instructional strategies, and classroom management. The teachers, regardless of educational attainment, length of service, and grade level assignment, have a similar level of teaching efficacy in terms of instructional strategies and classroom management. In the same way, teachers’ teaching efficacy in terms/ of classroom management is similar when they are grouped according to the length of service and grade level assignment. However, teachers’ teaching efficacy in terms of student engagement differs when they are categorized according to educational attainment.