Teachers are important social agents who affect students' cognitive and social behaviors, including students' self-directed use of technology for language learning outside the classroom. However, how teachers influence student behaviors may vary across cultures, and understanding how teacher influences vary across different cultures is critical to developing culturally adaptive approaches to enhance students' self-directed use of technology for learning outside the classroom. This study surveyed 418 undergraduate foreign language learners (190 from Hong Kong and 228 from the U.S.) on their intention to use technology for language learning outside the classroom, teacher influence and other psychosocial factors that may affect their technology use intentions. Structural equation modeling analyses of the survey responses indicated that teacher capacity support was consistently the most influential teacher practice affecting students' self-directed technology use across the two cultures, whereas teacher affective support and teacher behavior support were significant predictors for Hong Kong students but not for U.S. students. [Copyright of Educational Technology Research and Development is the property of Springer New York LLC.]