Teaching a language requires specific pedagogical knowledge and skills such as teaching grammar; designing appropriate activities and materials to enhance learners’ listening, reading, writing, and speaking skills; assessment of language proficiency; etc. However, none of the self-efficacy scales existing in the related literature reflect dimensions unique to language teaching. To fill this gap, the present study aims to construct and develop a teacher efficacy scale for language teachers. .In the first phase of the study, an instrument with 81 items designed using 5-point Likert scales was developed. In the second phase, the instrument (scale) was administered to 119 student teachers who had experience teaching English as a foreign language. Data were collected from three German universities. The seven-component solution explained 65.724% of the total variance and included 36 items. The analysis indicated that the Cronbach’s alpha value of the scale was 0.952, which shows that the Teacher Efficacy Scale for Language Teachers (T-eSLT) is a very valid and reliable instrument. The scale can be used as a tool for reflection and/or needs analysis in both pre- and in-service language teacher training contexts. The mentors can use the T-eSLT during student teacher observations to detect the skills that student teachers lack and provide constructive feedback accordingly.