<![CDATA[Critical thinking is one of the important competencies that need to be developed in learning because it helps students analyse information, solve problems, and make rational decisions. However, Catholic Religious Education classes still often use the lecture method, which causes low student engagement and has an impact on critical thinking skills that are not fully developed. This study aims to investigate the implementation of the Problem Based Learning (PBL) model in enhancing critical thinking skills among students, as well as to determine the effectiveness of this model in improving critical thinking skills in the context of Catholic Religious Education for Fase F students in Class XI-1 at SMA Katolik 2 Kabanjahe. The study used the Classroom Action Research (PTK) method, which was carried out in two cycles through the stages of planning, action, observation, and reflection. The study involved 31 students, with 23 students forming the sample group. Data was collected through observation, testing and documentation, while data analysis used descriptive quantitative and qualitative methods. The results of the study showed that the implementation of the PBL model was able to improve the quality of the learning process at every stage. Additionally, critical thinking skills among students also increased across all indicators, including objectives, questions about problems, information, interpretation and inference, and concepts. On average, critical thinking ability increased from 69% in cycle I to 82% in cycle II. Therefore, the Problem Based Learning model is effective in improving critical thinking skills in Catholic religious education.]]>
