Worldviews, historical backgrounds, and immediate surroundings can affect how one perceives sustainability and envisions it. Differences in schooling systems can impact the selection of pedagogical practices considered suitable for teaching about sustainability. Finnish and Namibian teacher training systems differ in multiple ways, and the status of teachers is higher in Finland than in Namibia. This study offers a novel perspective on language education by exploring how pre-service teachers envision sustainable development’s role in future language teaching and what pedagogical practices they see as sustainable in two markedly different contexts. Both Namibian (n = 33) and Finnish (n = 39) pre-service teachers’ reflections on sustainable development in language teaching were examined. The data was gathered from students attending a Finnish university and a Namibian university via a questionnaire. The responses were analysed using a summative content analysis approach. Finnish pre-service language teachers emphasise theme days, cross-curricularity, and digital materials when considering future sustainable pedagogical practices. Namibian pre-service teachers valued learning outside the classroom and real-life connections to sustainability. Pre-service teachers in both contexts considered it likely that sustainability’s visibility will increase in language teaching, teachers will be key drivers for change, and there is a growing need to improve teacher education to strengthen teachers’ sustainability skills.