Possible Worlds of Science Fiction

Possible Worlds of Science Fiction is an anthology of science fiction short stories edited by Groff Conklin. It was first published in hardcover by Vanguard Press in 1951. An abridged hardback version including thirteen of its twenty-two stories was published by Grayson & Grayson in 1952; an abridged paperback version including ten of its twenty-two stories was published by Berkley Books in July 1955 and reprinted in April 1956, November 1960, January 1962 and November 1968.

The book collects twenty-two novelettes and short stories by various science fiction authors, together with an introduction by the editor. The stories were previously published from 1936-1950 in various science fiction and other magazines. The Berkley version is divided into two sections, each with a separate introduction; "Part One: The Solar System," including the first five stories, and "Part Two: The Galaxy," including the last five stories.