OMNI was a science magazine and science fiction magazine published in the United States. It contained articles on science fact and short works of science fiction. The first issue was published in October 1978, the last in Winter 1995, with an internet version lasting until 1998. It was launched by Kathy Keeton, long-time companion and later wife of Penthouse magazine publisher Bob Guccione, who described the magazine in its first issue as "an original if not controversial mixture of science fact, fiction, fantasy and the paranormal"^[1]. Before launch it was referred to as Nova, but the name was changed before the first issue to avoid a conflict with the PBS science show of the same name, NOVA.

The magazine was initially edited by Frank Kendig, who left several months after the magazine's launch. Ben Bova, who was hired as Fiction Editor, was promoted to Editor, leaving the magazine in 1981. After Kendig and Bova, Editors of OMNI included Richard Teresi, Gurney Williams III, Patrice Adcroft, Keith Ferrell, and Pamela Weintraub (editor of OMNI Online). Kathleen Stein managed the magazine's prestigious Q&A interviews with the top scientists of the 20th century through 1998. Ellen Datlow was associate fiction editor of OMNI under Robert Sheckley for one and a half years, and took over as Fiction Editor in 1981 until the magazine folded in 1998. The very first edition had an exclusive interview with renowned physicist, Freeman Dyson, the second edition with American writer and futurist, Alvin Toffler.