The low critical thinking skills of students in Civics (PPKn) learning is a problem that requires serious attention at SMA Negeri 5 Bandar Lampung. This situation has prompted the need for innovation in learning approaches that can actively engage students while fostering higher-order thinking skills. The diversity-themed discussion learning model in PPKn was chosen as an alternative designed to address this challenge through contextual and collaborative learning. This research was conducted with a quantitative approach using a quasi-experimental one group pretest-posttest design . The discussion learning model was applied to the experimental class. Data were collected through critical thinking tests before and after treatment, then analyzed using various statistical tests, including effectiveness tests and tests of the model's contribution to learning outcomes. The results of the study indicate that the implementation of the discussion learning model is effective in significantly improving students' critical thinking skills. This model contributed 93.1% to the improvement of critical thinking skills, indicating that almost half of the students' achievements were directly influenced by the innovative learning approach through intense discussions among students. Thus, discussions are not only relevant but also strategic for implementation in PPKn learning to shape a generation that is critical, reflective, and respectful of diversity.