With the global spread of English, there are growing calls for English as a lingua franca (ELF) teaching (e.g., exposure to different varieties of English and opportunities to practice communication strategies) to help learners communicate in intercultural settings successfully. However, despite the widely acknowledged importance of ELF teaching, it is implemented only occasionally in classroom settings. While some previous research has explored challenges in ELF teaching, this study uniquely focuses on the Japanese context, which has not been fully explored yet. Therefore, this research explored Japanese teachers of English’s (JTEs’) attitudes toward ELF teaching and identified barriers preventing them from implementing ELF. The results from a questionnaire completed by 22 JTEs suggested that most of them demonstrated supportive attitudes, while there was a wide range of opinions toward ELF teaching. However, most participants rarely implemented ELF-related activities, primarily because of a lack of teaching time and a lack of familiarity with ELF. Based on an analysis of the results, the current study suggested that developing approachable ELF-related activities and introducing ELF content in teacher training programs were critical to effectively implementing ELF teaching in classrooms.