Religious education in public schools has been included in national curriculum, which is officially issued by Ministry of Education in Malaysia, Indonesia, Brunei Darussalam, and Thailand. These four countries are located in Southeast Asia, where multicultural and diversity of races and ethnicity are observed. Malaysia, Indonesia and Brunei Darussalam are having similarities in the number of Muslim populations, wherein Islam is the highest number of registered religion in the country. On the other sides, Thailand is a Buddhist country and majority of population are Buddhist. However, deep south of Thailand are dominant by Muslim. Hence, these four regions of the study are having similar multicultural society. Malaysia is applying national curriculum called Kurikulum Baru Sekolah Menengah (KBSM) in high school and religious education is a compulsory subject. Muslim student is to register for an Islamic education subject, meanwhile, Non-Muslim student is to register for Moral studies. Indonesia is applying national curriculum called School Based Curriculum (KTSP), where religious subject is called “Pendidikan Agama dan Budi Pekerti” and there are several religious subjects for all religions resided in the school for instance, Pendidikan Agama Islam dan Budi Pekerti is for Muslim. Brunei Darussalam is applying national curriculum called SPN21 (Sistem Pendidikan Nasional Abat ke21), where religious subject is called Islamic Religious Knowledge (IRK) for Muslims students. However, both Muslim and non-Muslim students are compulsory to register for Malay Islamic Monarchy subject. Finally, deep south of Thailand is applying National curriculum, where a religious subject is for all students in the school.