Today in South Korea, individuals of certain faiths are unable to take a wide range of state-administered qualifying examinations due to their religious convictions. The Constitutional Court of Korea has repeatedly refused their request for religious accommodations, such as an alternative test date for Sabbath or holy day observers who are unable to take exams on their original dates. The authors analyze the series of Constitutional Court decisions rejecting the need for such accommodation by focusing on the court’s use of its main analytical tool, the proportionality principle. These decisions reveal important shortcomings in the court’s application of the proportionality principle, including challenges inherent to proportionality and more specific deficiencies in the court’s application of the general principle. The article thus sheds light on how the proportionality principle is applied in the context of Korean constitutional jurisprudence and the resultant deprivation of protection for certain fundamental rights in Korea. The authors compare the court’s approach with that of courts in Spain, Switzerland, and the United States. They then propose a number of ways to improve the court’s proportionality analysis and its constitutional reasoning.