Chemistry is often perceived as a difficult subject by most students. This is largely due to the complexity of the material, which requires deep understanding and strong analytical skills. Based on the initial observation, several issues were identified, ranging from students appearing disengaged to low learning outcomes. To address these problems, the researcher proposed an alternative solution by implementing the Teams Games Tournament (TGT) type of Cooperative Learning model in the learning process. This study aims to examine the effectiveness of applying the Teams Games Tournament Cooperative Learning Model to the Reaction Rate topic. The subjects of this research were 27 eleventh-grade students at the private Islamic Senior High School (MA) Al Riyadhul Janah. The Classroom Action Research (CAR) was conducted in two cycles, each consisting of four stages. The success indicators of this study were an improvement in the teacher’s performance scores and an increase in the students’ average learning outcomes, reaching above the Minimum Mastery Criteria (KKM), which was set at 75. The findings revealed that the implementation of the Teams Games Tournament Cooperative Learning model was effective in improving students’ learning outcomes. In the second cycle, the average score increased to 79, showing a 31.6% improvement compared to the initial observation. However, the first cycle experienced a decrease of 13.3% from the initial results. This decline was caused by several factors, which were then addressed through reflection and improvement in the subsequent cycle. After implementing revisions in the second cycle, the Classical Mastery Level reached 70%, indicating that the research was deemed successful as it had met the predetermined success criteria.