Jonathan Ned Katz (born 1938) is a historian of lesbian, gay, bisexual, transgender, and heterosexual American history, who has focused on same-sex attraction and changes in the social organization of sexuality over time. His works focus on the idea, rooted in social constructionism, that the categories with which we describe and define human sexuality are historically and culturally specific, along with the social organization of sexual activity, desire, relationships, and sexual identities.