Purpose: The purpose of this paper is to explore how sustainable development (SD) is conceptualized by pre-service English language teachers in Turkey and design a specialized course syllabus on SD in English language teaching (ELT) in the light of the research findings. Design/methodology/approach: The study used a mixed-methods sequential explanatory study design and investigated the case of a state university in Turkey with the involvement of 133 pre-service English language teachers. Findings: The findings indicated that most pre-service English language teachers received no training or a course on SD in their whole education life and tended to associate SD mostly with the economic growth of a country, followed by education, social and ecological concepts. It was also found that the majority of the participants had a unidimensional view of SD. No direct links with ELT have been detected from participants' responses. The findings also pointed to the eagerness of the participants to receive an ELT-specific course on SD providing that the course involves interactive teaching and learning activities with reference to contemporary sources focusing on global and local issues, as well as studying the methods facilitating the incorporation of such issues into teaching practice. Research limitations/implications: This research is based on the experience of one Turkish university with limited quantitative and qualitative data. Practical implications: Based on the participants' knowledge, views and suggestions, this paper contributes to the existing literature by providing empirical evidence obtained from a local context and suggests a practical framework for a field-specific course syllabus aiming to enhance teacher candidates' knowledge, skills and values related to SD and its incorporation into ELT. Originality/value: To the best of the authors' knowledge, this is the first study seeking to explore pre-service ELT teachers' conceptualization of SD in Turkish higher education, and drawing on the research findings, the authors attempted to design a course syllabus targeted at pre-service teachers in ELT departments.