The essential premise of #MeToo is that, while large numbers of women are subject to sexual harassment and assault, this reality is not known to or understood by unnamed others. This article interrogates the subject of non-knowing that #MeToo points to but does not name, asking: who exactly does not know, and why? These questions provide the starting point to elaborate the concept of male ignorance. While this lexicon has been fleetingly deployed in canonical feminist works – where it denotes (...) something so obvious that it does not require explanation, functioning instead as a kind of feminist common sense – I develop it here so it might be put to greater use as a dedicated analytic. The work of Charles Mills, particularly his writings on white ignorance, provides a critical precedent in this regard. Following Mills in foregrounding the ideological operations of not knowing, I conceive male ignorance as a structure of concerted if unconscious epistemic occlusion which both stems from and serves to protect male privilege. As such, it plays a crucial role in securing the overall relation of domination and oppression within which gendered lives are lived. While male ignorance is itself multiple and has a variety of stakeholders, I argue that the non-knowing that surrounds sexual harassment and assault – which #MeToo draws attention to and seeks to undo – constitutes a paradigmatic manifestation, one in which cisgender heterosexual men have a particular stake. (shrink)