This study aimed to determine the improvement of mathematics learning outcomes of third grade students at SD Negeri 1 Abang in the academic year 2025/2026 after the implementation of the Discovery Learning model assisted by concrete media. The research employed Classroom Action Research (CAR) using the Kemmis and McTaggart model, which was conducted in two cycles. Each cycle consisted of planning, action, observation, and reflection stages. The subjects of this study were 28 third grade students of SD Negeri 1 Abang in the academic year 2025/2026, consisting of 19 male students and 9 female students. The data collection methods used were tests, observations, interviews, and documentation. Learning outcome data were analyzed using descriptive quantitative analysis, while observation, interview, and documentation data were analyzed using descriptive qualitative analysis. The results of the study showed an improvement in students’ mathematics learning outcomes in each cycle. In the pre-cycle stage, the students’ average score was 61.9 with an absorption rate of 61.9% and classical learning completeness of 39.3%. After the implementation of the action in Cycle I, the average score increased to 69.5 with an absorption rate of 69.5% and classical learning completeness of 75%. Furthermore, in Cycle II, the average score increased again to 75.7 with an absorption rate of 75.7% and classical learning completeness reaching 100%. Based on these results, it can be concluded that the implementation of the Discovery Learning model assisted by concrete media can improve the mathematics learning outcomes of third grade students at SD Negeri 1 Abang in the academic year 2025/2026.