This study investigated the influence of continued teacher education on the overall performance levels of local nonnative teachers of English in the Kutai Kartanegara Government Regency of East Kalimantan, Indonesia. The study aimed to appraise teachers' overall performance levels by examining three perceived indicators (English teaching confidence, English language proficiency, and attitude toward English). The study, employing a retrospective design, applied a developed questionnaire as a research instrument to gather quantitative data. The total sample was 72 participants: forty local Indonesian English teacher-participants and thirty-two administrator-participants who served in direct supervisory positions. This study revealed that participation in the continued teacher education program produced a significant perceived improvement in the teachers' English teaching confidence, English language proficiency, attitude toward English of the teachers, thereby leading to an overall enhancement of teacher performance. Due to the essential need for qualified English teachers in Southeast Asia, continued teacher education programs must become a primary focus of English teacher knowledge and English as a foreign language curriculum.