ONE, Inc. was a gay rights organization established in the United States in 1952.
The idea for an organization dedicated to homosexuals emerged from a Mattachine Society discussion meeting held on October 15, 1952. ONE Inc.'s Articles of Incorporation were signed by Antonio "Tony" Reyes, Martin Block, and Dale Jennings on November 15, 1952. Other founders were Merton Bird, W. Dorr Legg, Don Slater, and Chuck Rowland. Jennings and Rowland were also Mattachine Society founders. The name was derived from an aphorism of Victorian writer Thomas Carlyle: "A mystic bond of brotherhood makes all men one". The name was also a nod to referring to a gay person as "one of us". ONE was the first LGBT organization in the United States to have its own office, as such it's offices acted as a prototype LGBT community center
ONE readily admitted women, including–with their pseudonyms–Joan Corbin (as Eve Elloree), Irma Wolf (as Ann Carrl Reid), Stella Rush (as Sten Russell), Helen Sandoz (as Helen Sanders), and Betty Perdue (as Geraldine Jackson). They were vital to its early success. ONE and Mattachine in turn provided vital help to the Daughters of Bilitis in the launching of their newsletter The Ladder in 1956. The Daughters of Bilitis was the counterpart lesbian organization to the Mattachine Society, and the organizations worked together on some campaigns and ran lecture series. Bilitis came under attack in the early 1970s for "siding" with Mattachine and ONE, rather than with the new separatist feminists.
In January 1953 ONE, Inc. began publishing a monthly magazine called ONE, the first U.S. pro-gay publication, which it sold openly on the streets of Los Angeles for 25 cents. In October 1954, the U.S. Post Office Department declared the magazine "obscene" and refused to deliver it. ONE, Inc. brought a lawsuit in federal court, which it won in 1958, when the U.S. Supreme Court reversed the lower court ruling in One, Inc. v. Olesen based on its recent landmark First Amendment case, Roth v. United States. The magazine ceased publication in December 1969.