This study examines English language teachers' perceptions regarding teaching English in single-sex classrooms prevalent in religious vocational secondary schools, high schools, and other vocational and technical high schools in Türkiye. The study employs a qualitative methodology, utilizing semi-structured interviews with eight English teachers from three different religious vocational high schools. These teachers instruct classes in female-only, male-only, and both male and female classrooms separately. The data collected from the participant teachers was analyzed in regard to the advantages and disadvantages of single-sex classrooms in language teaching. The findings of this study may provide insights into pedagogical implications for policy-makers, curriculum developers, material designers, and language teachers.