Born in Portland, Maine, John Preston was an influential author of fiction and nonfiction, dealing mostly with issues in gay life. He was a pioneer in the early gay rights movement in Minneapolis. He helped found one of the earliest gay community centers in the United States, edited two newsletters devoted to sexual health, and served as editor of The Advocate in 1975. He was the author or editor of nearly fifty books, including such erotic landmarks as Mr. Benson and I Once Had a Master and Other Tales of Erotic Love. Preston's writing was part of a movement in the 1970s and 1980s toward higher literary quality in gay erotic fiction. He was an outspoken advocate of the artistic and social worth of erotic writings. His nonfiction anthologies, which collected essays by himself and others on everyday aspects of gay and lesbian life, won him the Lambda Literary Award and the American Library Association's Stonewall Book Award.

He also wrote the "Alex Kane" adventure novels about gay characters. These books, which included Sweet Dreams, Golden Years, and Deadly Lies, combined action-story plots with an exploration of issues such as the problems facing gay youth. Preston was among the first writers to popularize the genre of safe sex stories, editing a safe sex anthology entitled Hot Living in 1985. He helped to found the AIDS Project of Southern Maine. In the late 1980s, he discovered that he himself was HIV positive. He died of AIDS complications on April 28, 1994, aged 48, at his home in Portland.