This essay explores the role of the idea of an imaginary in understanding the diversity of the constitutional systems of the world. It adapts to constitutional purposes Charles Taylor’s explanation of an imaginary as ‘that common understanding that makes possible common practices and a widely shared sense of legitimacy’. It extrapolates general characteristics of imaginaries from Taylor’s account of the Western imaginary to assist understanding of the imaginaries of communities elsewhere and to explain how and why they may differ from each other. The essay argues that the idea of an imaginary may have explanatory power in a range of significant constitutional contexts in the current age of globalisation. It illustrates the point by examining the potential relevance of imaginaries in constitution-making and implementation; activities that have been widespread across the world since the end of the cold war, with mixed results. It concludes by speculating about the implications for imaginaries of the current world disorder and suggesting that imaginaries might have new applications in these unpromising conditions.