This chapter highlights the links between legitimacy and public relations, providing insights into how and why public relations is practiced. Specifically, this chapter defines legitimacy, and charts the evolution of public relations practices as they are related to legitimacy. It also discusses the legitimacy of the practice of public relations in society and its implications, as well as the legitimacy of the profession of public relations more broadly. The chapter acknowledges the idea that vying for legitimacy and reputation has become a central part of the practice of public relations in explaining organisations and maintaining support. It also underscores that when the profession of public relations is questioned as to its legitimacy, theoretically we may well argue that its existence, influence and power is a central part of contemporary society - whether used by the establishment or the people.