This research aims to improve the learning outcomes of Indonesian language students in grade V of SD Negeri 4 Kesu. The results of initial observation through the value of the education report on the Indonesian language subject for grade V students in the first semester of the 2025/2026 academic year show that student learning outcomes are still relatively low. This is proven because out of 19 students, there are 10 students who have not completed their learning outcomes, meaning that there are still 52.63% of students whose scores are below the standard of learning goal achievement criteria (KKTP), which is 70. This low learning outcome is rooted in the lack of variety of methods that facilitate students to discuss and share knowledge. Based on these data, the problem in this study was overcome by applying a cooperative learning model of the Two Stay Two Stray (TSTS) type, which is a group learning system with the aim that students can work together, be responsible, help each other solve problems, and encourage each other to excel. The type of research used is Class Action Research (PTK). The population of this study is grade V students at SDN 4 Kesu and the sample in this study is class 5 A. Sampling technique using purposive sampling techniques is a sample determination technique with certain considerations. Data collection techniques are tests, observations, documentation, and interviews. The data analysis techniques used are quantitative and qualitative data analysis. The results of the study showed that the application of the two stay two stray (TSTS) type cooperative learning model was able to improve the learning outcomes of Indonesian language students in grade V of SDN 4 Kesu, where in the first cycle it was in the sufficient category with a percentage of 68.42%, but in the second cycle it was in the very good category with a completion percentage of 89.47%. The results of this study prove that the application of the Two Stay Two Stray (TSTS) type cooperative learning model can improve student learning outcomes and can be used in other subjects.