Sustainability transformation calls for actors and agents of all types from all organisations and subsectors of society. Thus, sustainability‐themed and focused education has become a staple of higher education institutions, and the professionals and expertise produced—through learning of all sorts—have become an integral part of various organisations and their attempts to enact sustainability. A whole range of research and associated educational programmes have been founded, and various frameworks, for example those at the intersection of higher education and sustainability, and professionalism and climate change, have been study and development foci. However, few attempts at qualitative reflection and assessment have been made in this important field with its vital hypothesis that higher level of education, expertise, and professionalism will lead to higher societal sustainability impact by those educated actors. In this article, I propose that the Aristotelian concept of phronesis—as contextual and practical wisdom—can offer a framing for both reasoning about and assessing the qualitative side of being a climate change and sustainability professional. The conditions of being a sustainability professional, and the essence of phronesis thereof, are analysed from thematic in‐depth interviews with high‐level professionals, representing different organisations from various societal subsectors.