This paper explores how Southeast Asian marriage-migrant women in South Korea and their Korean language teachers view regional Korean dialects versus standard Korean. It also investigates in what ways these language ideologies impact the migrant women's language practices. The data were collected through ethnographic observation and semi-structured interviews with four marriage-migrants and their language teachers. The findings suggest that the migrants' use of the non-standard Korean dialect they initially acquired on arrival in Korea has contributed to their linguistic marginalization, particularly in the workplace. A consequent sense of inferiority about the way they speak Korean in turn creates barriers to the formation of pluralistic language ideologies. The women considered standard Korean a symbol of prestige and linguistic capital necessary to achieve membership in mainstream Korean society. For this reason, they actively invested in mastering standard Korean, which, for most, meant abandoning their regional Korean dialect. The paper concludes that the host society's awareness of the importance of linguistic and cultural diversity is crucial in addressing marriage-migrants' marginalization. It also suggests that including more bidialectal teachers in marriage-migrants' language classrooms could have a positive impact on their language learning by helping them use both regional Korean dialects and standard Korean appropriately.