Histories of 20th century British religion and sexuality, and that work which connects the two, have, until recently, been structured by the secularisation thesis, the assumption that politically and culturally Christianity's influence has steadily declined in the modern era. In the history of sexuality, it is commonly assumed that from the end of the Victorian era religious categories of sexual activity were replaced by scientific categories of sexual identity. This paper examines recent developments in the history and sociology of religion around the idea of the postsecular. Analysing religious developments in secularised societies in terms of religious change rather than a teleology of decline is starting to raise new questions in the history of sexuality. Postsecular analyses in the history of sexuality help us to understand the ways in which religion has continued to influence and shape understandings of sexual desire and identity in the 20th century.