This study explores how translanguaging can reimagine Vietnamese language instruction in U.S. higher education by challenging deep-rooted monolingual ideologies in Less Commonly Taught Language (LCTL) classrooms. Drawing on classroom observations and interviews with three LCTL instructors of Arabic, Vietnamese, and Portuguese, the research examines how teachers’ beliefs and institutional contexts shape language practices. Despite formal policies promoting “target language only” instruction, findings reveal that teachers and students frequently engage in translanguaging—strategically using multiple languages to enhance understanding, cultural connection, and communicative competence. The study discusses the potential of translanguaging pedagogy to validate the identities of multilingual learners, foster inclusive learning spaces, and expand language acquisition strategies. It concludes with practical implications for Vietnamese language programs, advocating for the intentional integration of students’ full linguistic repertoires, institutional support, and culturally responsive teaching.