The present study explores the relationship between teacher-efficacy and selected teacher variables, such as teachers’ demographic variables, self-efficacy, English proficiency, and teacher training experiences, of Korean English teachers. The study employed four questionnaires including Sherer et al.’s (1982) General Self-Efficacy Scale, Tschannen-Moran and Woolfolk-Hoy’s (2001) Teachers’ Sense of Efficacy Scale, Chacon’s (2002) Self-Reported English Proficiency Scale, and background information. The participants of the study were 120 Korean English teachers. The main findings of the study indicate that the participants’ standardized English proficiency scores exerted no significant influence on their teacher-efficacy. Yet, the teachers’ self-assessed English proficiency levels accounted for a significant amount of additional variance of their teacher-efficacy after controlling the variance explained by their self-efficacy, suggesting the significant impact of teachers’ positive assessment of their own English proficiency on their teacher-efficacy, regardless of their actual English proficiency. The study results also suggest that teachers’ professional training experiences generally contribute to their teacher-efficacy. Discussions and suggestions for future research are provided.