Higher education institutions (HEIs) contribute to the UN Sustainable Development Goals (SDGs), yet sustainability understandings and implementations vary widely across contexts. Addressing gaps in prior reviews, this study systematically analyzes dominant themes in recent open access literature on sustainability in HEIs. Using a qualitative thematic synthesis of 100 open access titles and abstracts from ScienceDirect (June 2025) and following Thomas and Harden (2008) and Braun and Clarke (2006), the analysis progressed from line-by-line coding to analytical themes. Six themes emerged: Curriculum and Pedagogy; Institutional Strategies and Governance; Technology and Innovation; Global and Cultural Contexts; Interdisciplinary Research and Social Responsibility and Community Engagement. Key insights include a pedagogical shift toward competency-based, experiential learning increasingly mediated by technology; the importance of whole-institution approaches despite persistent Global North-South disparities and a tension between global SDG frameworks and locally responsive implementation. The findings affirm that sustainability is a multidimensional requirement for HEIs, demanding transformation across teaching, research, administration and outreach. The study underscores the need for context-sensitive frameworks, equitable knowledge infrastructure and adaptable evaluation tools, while reinforcing the value of open, interdisciplinary scholarship for sustainable transitions.