Associational culture played an integral role in the reproduction of Britishness beyond the British Isles. Using the multiracial civil society in interwar Hong Kong as a case study, this chapter argues that middle-class residents there actively used civic associational culture to define and perform Britishness. It draws from five voluntary societies: the international networks of Freemasonry and the Rotary Club, as well as the League of Fellowship, the Hongkong Eugenics League, and the Kowloon Residents’ Association. In exploring the varying activities of these institutional networks, this Chapter demonstrates how Hong Kong’s colonial setting and its connections with China and other Asian port cities shaped the way urbanites in Hong Kong understood Britishness, and how these urbanites used their participation in civil society to define Britishness as a cosmopolitan belonging.