To address a paucity of knowledge on a way to enhance pedagogical content knowledge of sustainability (PCKS), the authors of the study developed an ecocriticism course and investigated its impact on English pre-service teachers' PCKS. A mixed-method convergent research design was employed. Forty-seven pre-service English teachers at one of the English education departments in Indonesia joined the course and received a pre- and post-questionnaire survey of PCKS. They were also required to generate English instructional ideas related to environmental sustainability at the end of the course in the open-ended questionnaire. The survey and open-ended questionnaire data were analyzed using a paired-sample t-test and content analysis. The results informed that the English pre-service teachers' PCKS, knowledge to create and provide learning opportunities for English learners to enhance the learners' sustainability capacity, was developed in the course. Accordingly, to orient English teacher education institutions towards sustainability, an ecocriticism course is suggested to integrate into the curriculum.