In July 2016, during a closed session with Polish bishops, Pope Francis stated, “In Europe, America, Latin America, Africa, and in some countries of Asia, there are genuine forms of ideological colonization taking place. And one of these is [the ideology of] ‘gender.’” Several months later, in the Republic of Georgia, the pope publicly condemned gender discourse as the “great enemy” in a “global war” of ideas. Around the globe, religious and other conservative actors are intensifying their attacks on feminist and LGBTQ+ scholarship and activism, casting advocates as “gender feminists” promoting a radical “gender ideology.” Language deployed by the Vatican, such as gender ideology, gender theory, and genderism, has been captured by right-wing enthusiasts to thwart emancipatory gender agendas worldwide. This article examines antigender campaigns as palpable transnational countermovements and considers their use of gender ideology as salient counterstrategies to feminist and LGBTQ+ social movements. By situating antigenderism within countermovement theory, the author shows that recent antigender activity transcends isolated and uncoordinated instances of resistance and instead operates within sophisticated and well-organized countermovements to defeat feminist and LGBTQ+ policy. By conceptualizing antigenderism as a countermovement, the author provides a useful framework for studying national and supranational antigenderism and for understanding the stakes in the tug-of-war among progressive social movements and countermovements for ontological and political control over the term “gender.”