The purposes of the present study are two-fold: (1) To examine whether social psychological variables, such as attitude and subjective norm, can predict South Korean English as a foreign language high school students’ intention to learn English, and (2) to identify the best social psychological model for sustainable second language learning in the context of South Korean English as a foreign language (EFL) learning. A total of 614 South Korean high school learners of English participated in the present study. Data collected from a survey questionnaire were analyzed using a structural equation modeling procedure. Results of the present study indicate that South Korean high school students’ attitudes toward learning English and subjective norms made a significant and independent contribution to the variance in their intention to study English. Among the three competing social psychological models examined in the current study, the theory of Planned Behavior and an expanded model of Gardner’s Socio-educational Model proved to be the most effective in terms of the strength of path coefficients and explanatory power. Theoretical and pedagogical implications are provided.