Marriage is one of the most integral unions regarded in Indonesia and Australia, despite the differences in their regulations; one of which, delved into this study, is interfaith marriage. An interfaith marriage, as the name denotes, is the unification of spouses who profess different religions. This union, dubiously, took practice in both countries, due to vast lands and abundant civilization. Indonesia is unscrupulously known for its rich multicultural diversity, therefore it is inevitable for couples to have interfaith marriages. Unfortunately, since the Circular of the Supreme Court was enacted in July 2023, it has been a challenge for Indonesian citizens to get their interfaith marriages legalised in the eyes of the law. Meanwhile, Australia is no less bountiful and some have married in interreligious circumstances. However, Australia fervently states the freedom of religion upon its citizens, as to whether or not they are atheists or religious, they are allowed to affirm their own beliefs. Hence, interfaith marriages are quite popular in Australia, be it amongst locals or foreign nationals. This thesis compares how marriage regulations in Indonesia and Australia are implemented towards interfaith marriages. This thesis encapsulates secondary sources as references such as Marriage Acts from both countries and the results from an interview.