Background: This study is motivated by the low levels of student engagement and learning outcomes in Islamic Religious Education, mainly due to the dominant use of conventional teaching methods, such as lectures, which limit student participation in the learning process. This condition underscores the need for a more innovative, student-centered learning model. Objective: The purpose of this study is to examine the improvement of Islamic Religious Education learning outcomes through the implementation of the Problem-Based Learning model among fourth-grade students at SD Dasar Negeri 23 Mukomuko. Method: The study employs Classroom Action Research conducted through four stages: planning, implementation, observation, and reflection. Data were collected using tests and observations to measure students’ learning outcomes and engagement before and after the intervention. Findings: The results indicate that implementing the Problem-Based Learning model significantly improved students’ learning outcomes, as reflected in increases in average scores from 62.25 in the pre-cycle to 70.75 in Cycle I and 86.5 in Cycle II, with the percentage of students achieving mastery rising to 95%. Conclusion: Problem-Based Learning is efficacious in improving learning outcomes in Islamic Religious Education. Originality/Value: This study contributes practical and pedagogical novelty to primary Islamic religious education by demonstrating the effectiveness of shifting from conventional teacher-centered lectures to the Problem-Based Learning (PBL) framework in cultivating active student engagement, problem-solving abilities, and cognitive achievement regarding Islamic education within regional elementary school settings, an area that remains relatively underexplored. These findings enrich the empirical literature and serve as a strategic reference for educators to design dynamic, inquiry-driven learning environments that make religious instruction more meaningful, applicable, and student-centered.