Background: The varying levels of teacher morale in elementary schools are particularly noteworthy, as they are closely linked not only to students’ engagement, behavior, and academic achievement, but also to teachers’ job satisfaction and emotional well-being. Objective: This study aimed to examine the influence of school principals’ leadership on teacher morale in Catholic elementary schools in Merauke, South Papua, Indonesia. Method: We employed a quantitative survey research approach to obtain data from 95 Catholic elementary school teachers in Merauke, South Papua, Indonesia. Obtained data were subjected to statistical analysis using simple linear regression analysis by employing Statistical Package for the Social Sciences version 21. Findings: The results of data analysis reveal a positive and significant impact of school principal leadership on the morale of Catholic elementary school teachers in Merauke, South Papua, Indonesia. Implication for Practice and Research: This finding implies that effective leadership practices by school principals play a crucial role in fostering teachers’ motivation, satisfaction, and overall well-being, which may in turn enhance the quality of teaching and learning in Catholic elementary schools.