Inter-religious education has become increasingly important in multicultural societies; however, the Islamic Education curriculum within Malaysia’s Kurikulum Standard Sekolah Menengah (KSSM) continues to emphasize moral values and social harmony without systematically incorporating inter-religious understanding, dialogue, and engagement with religious diversity. This study aims to develop an expert-validated inter-religious curriculum model for Islamic Education in Malaysia. Employing a qualitative Design and Development Research (DDR) approach, the study combined library research with Focus Group Discussions (FGDs) involving six experts in Islamic Education, Comparative Religion, and Curriculum Development selected through purposive sampling. Data were analyzed using inductive thematic analysis supported by ATLAS.ti. The findings identified four interconnected curriculum components: objectives focused on interfaith awareness, dialogical competence, and prejudice reduction; content introduced foundational knowledge of religions in Malaysia from historical, ethical, and cultural perspectives; teaching and learning strategies emphasized structured dialogue, inquiry-based learning, and guided experiential engagement; and assessment approaches integrated formative, summative, classroom-based, and project-based evaluation. Integrating Taba’s Curriculum Development Model with al-Syaibany’s principles of Islamic education, the proposed model offers a pedagogical framework for fostering interfaith literacy, respectful interaction, and multicultural understanding within Islamic educational contexts.