This article presents the findings of a qualitative research study on student teachers' perceptions of sustainability, specifically influenced by ecological citizenship and political solidarity. Research was conducted with 18 Graduate Diploma of Education (Primary) student teachers at one university, as they only have one year in which to train as teachers. A clear conceptualisation of Education for Sustainability is required for teachers to effectively implement the Australian Curriculum, which has sustainability as a cross-curriculum priority. Subsequently, Education for Sustainability is a key issue for teacher education and particularly within the short Graduate Diploma course. The findings showed that student teachers' perceptions of sustainability are shaped by aspects of ecological citizenship and political solidarity, and are informed by the local context. The findings also showed that the student teachers were moving from a more environmentally-centred conception of sustainability to a definition that included the other pillars of economic and socio-political sustainability. This article concludes with an argument for integrating the complex concepts of ecological citizenship and political solidarity within teacher education, so that student teachers graduate with the appropriate content knowledge to explore global citizenship and the ecological space with their future primary students.