Katherine Vandam Bornstein[1] (born March 15, 1948)[2] is an American author, playwright, performance artist, actor, and gender theorist.

In 1986, Bornstein started identifying as gender non-conforming and has stated "I don't call myself a woman, and I know I'm not a man" after having been assigned male at birth and receiving sex reassignment surgery.

[3]: xi Bornstein grew up just outside of Asbury Park, New Jersey, in an upper middle-class Conservative Jewish family of Russian and Dutch descent.

[5] Bornstein studied Theater Arts with John Emigh and Jim Barnhill at Brown University (Class of '69).

Bornstein joined the Church of Scientology, becoming a high-ranking lieutenant in the Sea Org,[6][7][8] but later became disillusioned and formally left the movement in 1981.

Laura Vogel, a friend of Kate's, launched a GoFundMe campaign on March 20 to help fund the cancer treatment.

[17] Bornstein made their Broadway debut in July 2018 in the play Straight White Men.

In 2009, Bornstein's Hello, Cruel World: 101 Alternatives to Suicide for Teens, Freaks, and Other Outlaws was a Lambda Literary Award Finalist for LGBT Nonfiction and Honorbook for the Stonewall Children's and Young Adult Literature.