The outbreak of COVID-19 has induced an abrupt shift from face-to-face instruction to online delivery mode for academic continuity. This research aims to explore the ecology of the pandemic-induced online English as foreign language (EFL) classrooms in Chinese middle schools and perceptions held by the English teachers, students, and parents. By analyzing data collected from 10, 576 questionnaires and eleven interviews, this study revealed how these participants played their respective parts in online EFL classroom ecology. Also, it was found that teachers’ evaluations of students’ learning performance (learning engagement and outcomes) and teacher-student interactions (in-class interaction, after-class interaction, and teachers’ feedback about homework) and their overall satisfaction of the online EFL classrooms were lower than that of the other two groups. In addition, major concerns of the participants about online EFL teaching and learning were identified, such as students’ vision damage and inadequate self-discipline, lack of face-to-face communication, and unstable Internet connection. Through presenting and discussing the research findings, this study is expected to provide implications and insights for foreign language educators, learners, and parents worldwide in adapting to online classrooms during public crises.