Conduct Unbecoming: Gays and Lesbians in the U.S. Military

Conduct Unbecoming: Lesbians and Gays in the U.S. Military from Vietnam to the Persian Gulf War is a 1993 book by American journalist Randy Shilts, in which the author traces the participation of gay and lesbian personnel from the Revolutionary War to the late 20th century.

The book was well received in a review in the Los Angeles Times which described it as "gripping reading" and "an irrefutable indictment of unconscionable government behavior in a cause that the military seems still unable to explain". The historian Lillian Faderman called the book "famous" in The Gay Revolution: The Story of the Struggle (2015).