This study aims to improve Indonesian language learning outcomes in fourth grade students of SDN Megamendung 03 through the application of the Jigsaw type cooperative learning model. Using a Classroom Action Research (PTK) approach with two cycles, the research was conducted on 18 students (10 boys and 8 girls) in the even semester of the 2019/2020 academic year. The results showed an increase in the average value of student learning outcomes from 60.2 in cycle I to 75.6 in cycle II, with an increase of 15.4. The percentage of learning completeness increased from 39% to 89%. Changes in student behavior in the aspects of activeness, cooperation, and participation also increased from an average score of 65 in cycle I to 94 in cycle II. These results prove that the application of the Jigsaw type cooperative learning model is effective in improving students' learning outcomes and activities in Indonesian language learning.