This article argues that the myth of ‘the sexual revolution’, increasingly accepted in Britain's national media between 1963 and 1967, played a central role in causing the real transformation of British sexual culture that occurred from the late 1960s. It also argues that Christian agency played an important role in the framing and the legitimation of this myth. Until 1963, British debates about sexual morality had been dominated by Christian arguments. In 1963 and 1964, the existence of a rapid, widespread, inexorable, secular, and antinomian transformation of sexual mores was prominently proclaimed by Christian commentators, who thought it an inevitable consequence of ‘secularization’, whereas secular commentators usually objected that this narrative was insufficiently evidenced. After its initial discussion in the mainstream media in 1965, the ‘sexual revolution’ narrative was increasingly articulated without explicit reference to Christianity, but it usually retained theologically inspired structural features inherited from earlier religious discussions. In the late 1960s, elite perceptions of inexorable sexual liberalization decisively legitimated rapid decensorship, wider access to the pill, and the reimagination of ‘normal’ sexual behaviour, thereby importantly shaping real popular change. In this way, Christian clergymen made a significant, early, unwitting, and hitherto unacknowledged contribution to Britain's sexual revolution.