Background: Indonesia’s multicultural society requires religious moderation to maintain harmony and prevent extremism. As a non-formal Islamic educational institution, Majelis Taklim plays a strategic role in fostering moderate religious attitudes and strengthening social cohesion at the grassroots level. Objective: This study aims to analyse the role, strategies, and contributions of Majelis Taklim in instilling religious moderation values within the Griya Sidomulyo community, Pekanbaru City. Method: This research employs a qualitative descriptive approach. Data were collected through in-depth interviews, participatory observation, and documentation involving administrators, preachers, congregants, and community leaders. Data were analysed through reduction, data display, and conclusion drawing, supported by triangulation to ensure validity. Results: The findings indicate that Majelis Taklim actively promotes moderation values through regular religious study sessions, thematic discussions, and social programs such as Jumat Berkah (Friday Charity Program) and Didikan Subuh (Early Morning Religious Education Program). These activities cultivate tolerance, balance, mutual respect, and social solidarity. Supporting factors include active participation, qualified preachers, and strong community engagement, while financial constraints and coordination challenges remain obstacles. Conclusion: Majelis Taklim functions as an effective grassroots institution for cultivating religious moderation and strengthening social harmony in heterogeneous urban communities. Originality/Value: This study provides empirical and contextual novelty in the field of nonformal Islamic education and community sociology by revealing the effectiveness of integrating thematic da'wah programs and social community initiatives such as Friday Charity and Early Morning Religious Education alongside community leader engagement regarding the cultivation of religious moderation values within the context of grassroots learning assemblies in heterogeneous urban housing communities, which has received limited scholarly attention compared to formal educational settings. These findings enrich empirical evidence and serve as a strategic reference in grassroots religious governance, empowering community based religious institutions, and formulating social cohesion initiatives at the neighborhood level.