There are a growing number of university sustainability efforts, but the literature provides limited information to help universities decide if they are focused on sustainability aspects important to their stakeholders. To address this gap, Canadian student leaders' conceptualizations of sustainable development (SD) and sustainable universities were investigated using a mixed methods approach with qualitative interviews and nested quantitative concept checklists. Themes were developed through thematic analysis and compared with support for checklist concepts to explore similarities and differences between the datasets. Conceptual variance existed between student leaders concerning sustainability; there was greater agreement between participants regarding conceptualizations of sustainable universities. Participants also believed that universities have a responsibility to lead by example and to educate both students and the greater community about sustainability. This research provides insight into the conceptualizations of a key university stakeholder, the importance of localized discussions of sustainability and encouragement for universities to engage in sustainability.