This article examines the contributions made towards eugenic thought in the late nineteenth and early twentieth centuries by Havelock Ellis (1859-1939). Ellis was a significant social reformer who worked on the problems of sexuality from a scientific-naturalist secular perspective. In the later phases of his work, after he had completed much of his writing on sexuality, Ellis concentrated on issues of feminism and eugenics--problems he thought were interlinked. In this paper, I integrate his ideas about these subjects, and consider the ways in which Ellis and other liberal social reformers created a 'eugenic subject' in order to frame their arguments about social problems.