Scholarship has neglected relationships between the "hidden curriculum" and environmental sustainability. The prevalence of ELT worldwide coupled with the importance of behavioral norms in sustainability makes such examinations necessary. In response, the objective of this project was to investigate depictions of norms with implications for environmental sustainability in the hidden curriculum of English language teaching (ELT) materials from Japan. Methodologically, a content analysis of 3837 ELT materials used across Japan was conducted to understand implicit portrayals of such norms. Results indicated that many behaviors normalized in these materials were not sustainable. The promotion of tourism to stereotypical locales and a consumerist stance were especially notable. Since Japanese formal education is ostensibly committed to sustainability, this research illustrates how the hidden curriculum can work at cross purposes to the official curriculum. It also suggests a framework for assessing environmental sustainability within the hidden curriculum beyond ELT and outside of Japan.