Given the escalating global energy consumption and the concurrent economic and energy crises, energy-saving behaviour must be adopted on a large scale. Universities that are energy-intensive institutions should be one of the institutions where energy-saving behaviour is widely adopted. Academics devote a substantial portion of their time to their offices, which leads to increased energy usage. However, no study has investigated academics' energy-saving behaviours in the literature. Most studies focus on students or employees in various organizations. Our study tries to cover the gap by examining the energy-saving behaviour of academics in four countries (Romania, Bulgaria, Turkey, and Slovakia) based on the expanded Theory of Planned Behaviour. A questionnaire was distributed to 228 academics from the four countries to gather data. The research hypotheses were tested using partial least squares structural equation modelling. The findings show that individual factors (attitude and perceived behaviour control) influence the energy-saving intention of academics but not the organisational factors due to the weak identification with their universities. The study offers valuable insights for policymakers seeking to promote energy-saving programs in academic institutions. The academics can be seen as role models for their students which emphasizes the need to study more their sustainable behaviours.