The concept of 'regional tourism' has gained salience in Asia since the 1990s. The traditional practice of single-country tourism development is increasingly complemented by cross-border collaborations in planning and promotion. Through these transnational practices, new tourism spaces are being configured with region-states emerging alongside nation-states. In this paper I explore the concept of Asian regional tourism from the perspective of Singapore. As a city-state with scarce land resources, Singapore has turned to regionalism (or 'regionalisation') to overcome its spatial constraints, and to stimulate its tourism industry. I have two main aims in this paper. Conceptually, I argue that regional tourism takes a number of distinct spatial configurations, as exemplified by the case of Singapore. Empirically, I reveal that tourism regionalisation brings manifold opportunities to a small country like Singapore, but that it also generates many challenges hitherto never experienced. Political sensitivites within Asia, incompatible working styles between societies, and cultural differences emerge when countries interact with each other.