As with many other countries, South Korea is increasingly ethnically and linguistically diverse -- the result of changing patterns of migration and transmigration in a globalised world. However, despite these developments, South Korea retains a strong emphasis on public linguistic homogeneity in standard (Seoul-based) Korean, its national language, and related linguistic hierarchies of prestige that privilege this standard at the expense of other Korean language varieties. This combination is demonstrated clearly in the case of North Korean refugees to South Korea. Despite speaking the same language, their dialect and accent are consistently pathologized in South Korean higher education (HE) and the wider society. This article reports on a study of the experiences of linguistic discrimination faced by North Korean refugee students in South Korean HE, its often-negative consequences on North Korean students' social and academic identities, and their strategies for mitigating and, at times, actively contesting this discrimination. The article concludes that, despite South Korea's increasing demographic and, related, linguistic diversity, little has been achieved yet in addressing, and changing, the endemic linguistic discrimination that North Koreans face daily in HE and the wider South Korean society.