Weber's legitimacy theory has been diffused widely throughout the corporate and political context but not to the sporting world. This paper adopts Weber's legitimacy theory to better understand the context of Australian sport, particularly as it relates to soccer's standing in the culture. For the majority of its Australian existence, soccer was not part of the mainstream, and academic and other writing has labelled it illegitimate. However, despite appropriating the illegitimacy label, no theoretical model has been applied to the assertion. Weber's Theory of Legitimacy depicts three types of legitimacy; charismatic, legal/rational and traditional. This qualitative research utilized interview data collected from a purposive sample (N=22) of the influential people who determined soccer's legitimacy as a result of the sport's restructure in 2003, through to the nationally acclaimed triumph of winning the men's Asian Cup in 2015. The data was then compared against Weber's theory to better understand soccer's transformation, showing that Australian soccer was legitimised by the recruitment and leadership of Frank Lowy (charismatic), the intervention of the Federal Government (legal/rational) and the inter-generational growth of the sport's popularity and participant base (traditional). This paper not only attempts to theorise Australian soccer but also raises some important questions regarding Australian soccer studies in general.