The Young Conservatives were primarily a social club, hosting dances, beauty contests, car rallies and winning endorsements from sports stars. They made a virtue of this apolitical reputation to recruit a mass, middle-class membership, and with rhetoric of service and citizenship embedded themselves in local civil society. This article reflects on why this associational culture has been neglected by political and social historians. In the approach of Raphael Samuel's ‘Lost world of British Communism’, it explores the worldview and lifestyle of YCs in 1950s and 1960s Britain, drawing on national, local, and oral sources. Boasting of being ‘the free world's largest youth political movement’ it was a considerable political resource and confounds Conservatism's aged public image in this period. The article accounts for the Ycs' falling membership through the 1960s and discusses its legacy. Decline came as it experienced social and cultural change, as the value of mass party membership diminished and as, after the Macleod report, YCs sought to become more conventionally ‘political’. The resulting debates about politics–social mix are illuminating about political culture more generally. It argues the YCs were not simply victims of social change, but that the decision to become ‘political’ was also a factor. Until the later 1960s it contends the YCs attest to the persistence of strands of Conservatism described by interwar historians like McKibbin and Light – an associational appeal, whose light touch deftly avoided the appearance of being partisan in anything other than name.