With particular reference to religious education, this article provides an account of the campaigns of Secularists and Humanists in England in the 1960s and 1970s and locates them within their broader religious context. These campaigns, which have been both underplayed and overstated in the existing historiography, failed to garner the levels of support required to fulfil their ultimate aims. Nevertheless, Secularists and Humanists did make a significant contribution to public and political discourses at the time and created opportunities with the potential to exert influence over the development of religious education, collective worship and moral education. Their involvement was welcomed, indeed fostered, by many leading Christians and religious educationists. Secularist and Humanist campaigns also precipitated parliamentary discussion and provoked considerable opposition from Christians in other quarters. Finally, some observations are made about the ways in which this episode in the religious history of education can contextualise comparable contemporary debates. (Contains 275 footnotes.)