YouTube has the potential to significantly impact Korean millennials’ daily lives. Nevertheless, it remains unclear whether the value of YouTube can be explained by Korean students’ learning needs and practice. This qualitative study attempts to add a new dimension to possible ways of using YouTube for educational purposes. Focusing on narratives of first-year Korean international students studying in the U.S., this study examines the ways in which using YouTube contributes to students’ linguistic and cultural diversity. Findings reveal that YouTube helps expand students’ perspectives on cross-cultural understanding. The educational use of YouTube also leads students to academic pursuits and engagement during studying abroad by developing content knowledge and skills in English. It further enables students to enhance their knowledge of English as a global language by taking ownership. Ultimately, YouTube plays an indispensable role in supporting Korean international students’ academic and social progress in the transitional phase from their home to host countries. From these findings, and in response to the post-COVID era, the implications for the new normal in education using social networking sites, YouTube in particular, are discussed for effective multilingual and multicultural education in South Korea.