Queer theory is a new theory about gender. It is relevant to early childhood educators who wish to find new ways of understanding and challenging persistent gender stereotypes. The theory links gender stereotypes to the norms of heterosexuality. It is definitely "not" a theory about gay and lesbian identity. Queer theory is "queer" because it questions the assumption that there is any "normal" expression of gender. Researchers have been using feminist and post-structural theories to analyze the ways in which gender stereotypes are constructed, how children make sense of gender and actively engage in negotiating their own gender identities, and how children's meaning making and engagement related. In this article, the authors offer a review of research that uses queer theory to rethink gender in early childhood education. This review is conducted in three steps. First, it explains how feminist post-structuralist theories have shifted the debate on early gender identity from either a nature-or-nurture framework to a more nuanced understanding of how children's gender is constructed. Second, it shows how queer theory builds on feminist post-structural understandings of gender by linking the construction of children's gender identities with the powerful influence of heterosexual norms. Third, it explores how some researchers and teachers are using a "queer eye," informed by queer theory, to rethink children's play and to critically reflect on and influence professional practice. The article concludes with specific implications for practitioners.