Sustainability leadership entails the processes, which leaders, policymakers, and academics undertake in order to implement sustainable development policies and other initiatives within their organizations. It encompasses approaches, methods, and systemic solutions to solve problems and drive institutional policy towards a more sustainable organization. Higher Education Institutions (HEI) play a particularly important role, especially with regard to their institutional leadership role in promoting sustainable development. There is a paucity of research focusing on sustainability leadership in universities. In order to address this gap, this paper discussed the concept of sustainability leadership based on literature and empirical insights. The study aimed to understand the main characteristics of sustainability leaders at HEI and the main challenges they are confronted with. Secondary research questions involved gender issues and positive outcomes of sustainability leadership. The empirical component of the study consisted of an online-questionnaire survey performed among leaders (n = 50) from a set of universities in 29 countries. The sampling scheme was purposive, based on the membership in the Inter-University Sustainable Development Research Program (IUSDRP). The study was explorative in nature, and the descriptive statistics were used for the analysis. Due to the purposive sampling, the participants from top management positions could be considered as experienced, and their views were assumed to be information-rich. With a self-evaluation, the respondents described their leadership style and their usual traits, with inclusive style and systemic thinking being predominant in the sample. Regarding the skills, the respondents selected the ability to innovate, to think long-term, and to manage complexity from a pre-defined set of options. Connectedness with interdisciplinarity and knowledge about organizational settings, as well as global challenges and dilemmas, were stated as important issues related to the knowledge required for being a leader. Regarding requirements for a change towards more sustainable universities’ curriculum adaptation, investments in education for sustainable development (ESD), sustainable procurement, and reporting were mentioned. The study also revealed that gender issues were taken seriously among the sampled institutions, which is an encouraging trend. Challenges seen in implementing sustainability leadership are, for instance, a lack of interest by the university administration and among some members of the academic community, as well as lack of expertise and materials or resources. Based on the empirical insights, a set of measures were listed and which may be adopted in the future, so as to allow leaders of Higher Education Institutions to enhance their sustainability performance.