Despite its legacy of feminist leadership and a continued female majority, the Nonhuman Animal rights movement has exhibited structural sexism across its various waves of protest. This institutionalized sexism not only inhibits women’s ability to protest safely and effectively, but also permeates the activist imagination and aggravates interpersonal violence. Even Nonhuman Animals as a feminized group are unwittingly disparaged in popular campaigns. This essay suggests that structural sexism in the Nonhuman Animal rights movement is nourished by its patriarchal organization, specifically its decision to professionalize. Twenty-first century vegan feminist activism on the margins has been able to circumvent the hegemony of professionalized power and challenge taken-for-granted bureaucratic structures. Yet, despite indications that vegan feminist activists are influencing the movement dialogue, the movement’s patriarchal norms have encouraged considerable pushback. Indeed, the patriarchal influence of professionalization has even created division between second wave and third wave vegan feminists.