This study was motivated by fourth-grade students’ difficulties in reading comprehension, particularly in identifying main ideas, organizing information, and understanding instructions in Indonesian. The frequent use of regional languages in daily communication may create challenges when students encounter Indonesian as the language of instruction. This study aimed to improve students’ reading literacy and learning outcomes through the mind mapping model, which visually organizes keywords, main ideas, and conceptual relationships. The study employed participatory Classroom Action Research (CAR) involving 22 fourth-grade students (12 boys and 10 girls) at State Elementary School 04 Sulit Air, Solok, during the odd semester of the 2025/2026 academic year. The research was conducted in two cycles, each consisting of three meetings covering planning, implementation, observation, and reflection. Data were collected through observations, learning achievement tests, and documentation. Results showed improvement from Cycle I to Cycle II. In Cycle I, 11 students (50%) achieved the minimum mastery criterion, with an average score of 73.0. In Cycle II, 20 students (90.91%) achieved mastery, with an average score of 87.7. Thus, the average score increased by 14.7 points, while classical mastery increased by 40.91 percentage points, exceeding the 75% target. The findings indicate that mind mapping supported improvements in reading comprehension, main-idea identification, and classroom participation.