Hong Kong, as a leading financial hub whose denizens’ foremost preoccupation has been the pursuit financial success, has long been assumed to play a limited role in the geopolitics of the region. However, its unique status as a semi-autonomous and open city under the otherwise authoritarian rule of Beijing means that it has always been ripe for conflict, influence, and subversion not only from the West but also from China, which increasingly seeks to project its power beyond its shores. Unlike its fortified neighbours situated at the fault line in the ongoing US–China rivalry, such as Taiwan, the battle over Hong Kong has never been about the high politics of military security. Yet, we argue that Hong Kong is no less consequential to the rivalry. We discuss how Hong Kong has been used for leverage in the two superpowers’ competition in other non-military issue areas, as a resource to promote their respective mode of governance (authoritarianism versus liberal democracy), and as an example for countries contemplating the choice of a Chinese- versus American-led international order.