["TESOL Quarterly, EarlyView. ", "\nAbstract\nIn the past couple of years, the use of Generative Artificial Intelligence (GenAI) technologies has received increasing attention in academic contexts. However, the overall ecological system of GenAI literacy has remained unclear to scholars and educators in English as a foreign language (EFL) settings. To fill the gap, the present study employed Bronfenbrenner's (1977) ecological system theory to evince factors that shape Chinese TESOL teachers' GenAI literacy. A focus group interview and a narrative frame were used to gather the needed data. The results of thematic analysis revealed that a wide range of factors at five layers constitute TESOL teachers' GenAI literacy. In particular, it was found that GenAI literacy is affected by 14 factors at micro, meso, macro, exo, and chrono‐systemic levels. The study highlights the importance of cultivating an atmosphere of GenAI technology acceptance and adoption in EFL settings that strongly fosters GenAI literacy development among educators. Implications at the theoretical and practical levels are further discussed in the study to augment GenAI literacy of TESOL teachers, teacher educators, and policymakers.\n"]