Nonbinary gender identities have quickly gone from obscurity to prominence in American public life, with growing acceptance of gender-neutral pronouns, such as “they, them, and theirs,” and recognition of a third-gender category by U.S. states including California, Colorado, Minnesota, New Jersey, Oregon, and Washington. People with nonbinary gender identities do not exclusively identify as men or women. The increased visibility of a nonbinary minority creates challenges for other rights movements, while also opening new avenues for feminist and LGBT advocacy. In this seminar, Jessica Clarke asks what law and policy would look like if they took nonbinary gender seriously. She assesses the legal interests in binary gender regulation in areas including law enforcement, employment, education, housing, and health care, and concludes these interests are not reasons to reject the broader project of nonbinary inclusion.