Who first theorized Queer theory?
Queer theory
Teresa de Lauretis
Queer theory is a field of critical theory that emerged in the early 1990s out of the fields of queer studies and women's studies. Queer theory includes both queer readings of texts and the theorization of 'queerness' itself.  Heavily influenced by the work of Lauren Berlant, Leo Bersani, Judith Butler, Lee Edelman, Jack Halberstam,[1] and Eve Kosofsky Sedgwick, queer theory builds both upon feminist challenges to the idea that gender is part of the essential self and upon gay/lesbian studies' close examination of the socially constructed nature of sexual acts and identities. Whereas gay/lesbian studies focused its inquiries into natural and unnatural behavior with respect to homosexual behavior, queer theory expands its focus to encompass any kind of sexual activity or identity that falls into normative and deviant categories. Italian feminist and film theorist Teresa de Lauretis coined the term queer theory for a conference she organized at the University of California, Santa Cruz in 1990 and a special issue of Differences: A Journal of Feminist Cultural Studies she edited based on that conference.