In 2000, the United Nations Security Council passed resolution 1325, which addressed, for the first time, the experience of women and girls during conflict and the need to consider gender in peacebuilding. From this landmark resolution, a groundbreaking Women, Peace and Security (WPS) agenda has evolved, guided by ten total Security Council resolutions. But to this point, the WPS framework and related scholarship has yet to meaningfully include queer and trans women in their programmatic work and conflict interventions. Queering Women, Peace and Security fills this gap by applying queer theory to feminist efforts to ensure a gender perspective is promoted by the WPS agenda. Engaging with WPS documentation, examples of implementation, and interviews with practitioners, Jamie J. Hagen examines how the needs of LGBTQ people in conflict and peacebuilding are considered within the current architecture and practices. In particular, she identifies the interchangeable use of the words "gender" and "women," which betrays a larger analytical failure to think outside a binary categorization of gender. Informed by this analysis and interviews with leaders from Northern Ireland and Colombia, Hagen outlines steps those implementing the WPS agenda can take to work in collaboration with queer and trans communities in their gender, peace, and security work.