Organisation development (OD) roles and skills are in demand in practice, yet they receive scant attention in the academic literature. Using the theoretical lens of population ecology, this study examines the evolution of OD through a 40-year empirical study. The paper extends current thinking by contrasting the research of academic scholars on the evolution of the human resources management (HRM) profession in the UK and USA. It also presents implications of the data for the future, in practice, and as an academic subject. The methodology applied in this longitudinal study identifies growth and content analysis of job advertisements in the relevant trade press. A key finding of the study is that whilst it has achieved legitimacy in...