Higher Education (HE) systems comprise institutions whose function is to support, develop and deliver teaching and learning at post-secondary or tertiary level. Many HE institutions also address research and/or provide enterprise services in partnership with other organisations in the private, public and third sectors. HE systems have therefore a key role in the development of citizens, society and the economy, including the knowledge, skills and behaviours needed to support sustainable development. A sustainable Higher education (HE) system may be defined in terms of the network of local, national and international HE institutions and their systems that sustain the core functions of HE, including the delivery of teaching and learning, research, and outreach, by addressing social, economic, and environmental targets and constraints influencing the HE institutional context. A sustainable HE system not only sustains the functions of HE institutions but supports the aims of sustainable development by advancing citizens' knowledge and skills to meet the needs of society and the economy and by promoting stewardship of the natural and built environment. This article examines the concept of sustainable HE systems and three key approaches to promote environmental sustainability and the Sustainable Development Goals (SDGs) established by the United Nations in 2015. These approaches include: greening the curriculum to encompass Education for Sustainable Development (ESD); greening campus buildings and site operations; and designing HE teaching and learning delivery systems, such as distance and online education systems, to minimise negative environmental impacts and carbon dioxide emissions. Definition A sustainable Higher education (HE) system may be defined in terms of the network of local, national and international HE institutions and their systems that sustain the core functions of HE, including the delivery of teaching and learning, research, and outreach, by addressing social, economic, and environmental targets and constraints influencing the HE institutional context. A sustainable HE system not only sustains the functions of HE institutions but supports the aims of sustainable development by advancing citizens' knowledge and skills to meet the needs of society and the economy and by promoting stewardship of the natural and built environment.