Hubert Collings Kennedy (born 1931) is an American author and mathematician.

Kennedy was born in Florida and studied mathematics at several universities. From 1961 he was professor of mathematics, with research interest in the history of mathematics, at Providence College (Rhode Island), He spent three sabbatical years doing research in Italy and Germany. He published a definitive biography of Giuseppe Peano who conceived modern mathematical notation.

Kennedy came out as gay on the cover of the magazine The Cowl, and, along with Eric Gordon, was part of the first Gay Pride parade in Providence, Rhode Island, which was held on June 26, 1976.

In 1986 Kennedy moved to San Francisco, where he continued his historical research, now on the beginnings of the gay movement in Germany. He has over 200 publications in several languages, from an analysis of the mathematical manuscripts of Karl Marx and a revelation of Marx's homophobia,^{[citation needed]} to theoretical genetics and a proof of the impossibility of an organism that requires more than two sexes in order to reproduce.^{[citation needed]} In addition, Kennedy has written biographies of the Italian mathematician Giuseppe Peano and the German homosexual emancipationist/theorist Karl Heinrich Ulrichs, and has edited the collected writings of Ulrichs. His translations of the boy-love novels of the German anarchist writer John Henry Mackay and his investigations of the writings of Mackay have helped establish Mackay's place in the gay canon.

Kennedy married his longtime companion Don Endy in 2014.