This paper aims to create a comprehensive model of a sustainable university by combining the concepts of sustainable universities with various university assessment systems, including national and international university accreditation, professional accreditation, and global university ranking. The model conceptualisations of university sustainability and university assessment systems were taken from different existing models in higher education. These were summarised and conceptualised to create an integrated model of a sustainable university and its assessment criteria. It was found that the goals of both systems corresponded with one another. Thus, the aim of establishing sustainable universities is also in line with already existing university goals, such as achieving excellence in organisational and academic goals. An innovative model combining university sustainability and university assessment systems would be beneficial in simplifying the complex and multidimensional nature of a sustainable university and may portray a more attainable and relatable view of university sustainability overall.