Unlike his bourgeois economic nationalism or diplomatic posturing on behalf of the developing world, Mahathir Mohamad's encounter with Islam remains a largely understudied aspect of his 22-year rule of Malaysia (1981–2003). There is a marked reluctance to take seriously his pronouncements on Islam and engage with his representations of what being-Muslim should entail in the modern world. This essay takes the view that Islam, in fact, represents a significant component of the former Malaysian prime minister's political repertoire, and that an analysis of what may be described as “Mahathir's Islam” can provide a compelling alternative account of his momentous premiership. It argues that while Mahathir's engagement with Islam was fraught with contradictions and has produced a number of negative consequences that affect Malaysian society as a whole, his discourse also contained the ingredients of what Bellah and Hammond (1980) have famously described as civil religion. Mahathir's public representations of Islam – in particular, his championing of the individually responsible believer and interpretation of the message to the Prophet Muhammad as a this-worldly and pro-active “theology of progress” – can thus provide religious validation to the cosmopolitanism of the street that has helped underwrite the social peace of multi-religious Malaysia.