Limited teacher competence in classroom management can hinder children’s engagement and reduce the effectiveness of learning in early childhood education settings. This community service program aimed to strengthen the classroom management competence of teachers at TK Kusuma Mulia, Gedangan Hamlet, Klampisan Village, through participatory mentoring. The program employed a Participatory Action Research approach conducted in two cycles, each consisting of planning, action, observation, and reflection. Six teachers participated in the program, while changes in the engagement of 21 children were observed in aggregate. Data were collected through participatory observation, semi-structured interviews, focus group discussions, competency assessments, and documentation. The data were analyzed using interactive qualitative analysis and descriptive quantitative techniques. The mentoring activities included conceptual reinforcement, the collaborative development of classroom rules and routines, demonstrations, guided teaching practice, peer observation, feedback, and reflection. The findings indicated that the teachers’ average classroom management competency score increased from 66 at baseline to 76 in the first cycle and 83 in the second cycle. Five of the six teachers, or 83.3%, achieved the good competency category. This improvement was accompanied by a decrease in the proportion of children who were unable to maintain attention from 28.6% to 9.5%, passive participation from 28.6% to 14.3%, and leaving activities without instruction from 28.6% to 9.5%. By the end of the program, all teachers had also completed written reflections. These findings indicate that participatory, contextual, and practice-based mentoring can strengthen teacher competence, improve children’s classroom engagement, and foster a reflective culture that supports continuous improvement in early childhood learning.