This thesis interrogates the concept of ‘Moderate Islam,’ a concept that is routinely referred to in Western discourse about Islam, but which engenders considerable debate within the Muslim world. Filling a gap in the scholarly literature, the thesis puts forward the argument that ‘Moderate Islam’ is essentially a Western geo-political construct that is conceived as the binary opposite of ‘Radical Islam’ as a way of making sense of Islamic radicalisation and the US war on terror. Juxtaposed against this, orthodox or mainstream Islam’s understanding of ‘Moderation’ is shown to be intrinsically embodied in the theological concept of ‘Wasatiyyah’. A case study of 29 largely academic Turkish and Australian respondents follows in order to demonstrate not only the ambiguity of the term ‘Moderate Islam’, but also its complexity depending on whether it is viewed through geopolitical, theological or jurisprudential lenses. Because it is associated with the Gülen movement, for example, ‘Moderate Islam’ acquires an entirely different complexion within a Turkish context. Ultimately, the thesis raises the possibility of achieving a greater understanding of ‘Moderate Islam’ vis-à-vis Wasatiyyah through a consideration of both Western and Muslim epistemologies.