In our introduction to this special issue on the histories of feminism, gender, sexuality, and the psy-disciplines, we propose the tripartite framework of "feminism and/in/as psychology" to conceptualize the dynamics of their conjoined trajectories and relationship to gender and sexuality from the late 19th through the late 20th centuries. "Feminism and psychology" highlights the tensions between a political movement and a scientific discipline and the efforts of participants in each to problematize the other. "Feminism in psychology" refers to those historical moments when self-identified feminists intervened in psychology to alter its content, methodologies, and populations. We propose, as have others, that these interventions predate the 1970s, the period most commonly associated with the "founding" of feminist psychology. Finally, "feminism as psychology/psychology as feminism" explores the shared ground between psychology and feminism-the conceptual, methodological, and (more rarely) epistemological moments when psychology and feminism made common cause. We suggest that the traffic between feminism and psychology has been persistent, continuous, and productive, despite taking different historically and geographically contingent forms.