This article explores the increasing professionalisation of school business practitioners in the state school system in England. Often referred to a 'school business managers' or 'school business leaders', this cohort of the school workforce have been increasingly tasked with leading crucial site-based management functions in schools, such as finance and budgeting, human resources and school operations. As this area of practitioner activity has grown over the last two decades, 'school business leadership' has increasingly been positioned by education policy makers and professional bodies as a distinct field of practice within the school system. However, despite increasing recognition of the value of school business leadership within the school system, there is evidence of continued tensions around the inclusion of such practitioners in matters of leadership. Further, there is a paucity of scholarly research exploring school business activity and the increasing professionalisation of its practitioners. Therefore, this article serves to contribute to this gap by exploring the evolution of school business practitioners and their positioning within the wider field of education in England. It argues for further research in England and for knowledge exchange with other education contexts to share insight and explore future potential.