Speculative fiction as a category ranges from ancient works to both paradigm-changing and neotraditional works of the 21st century. Speculative fiction can be recognized in works whose authors' intentions or the social contexts of the versions of stories they portrayed are now known, since ancient Greek dramatists such as Euripides (ca. 480–406 BCE) whose play Medea seems to have offended Athenian audiences when he fictionally speculated that shamaness Medea killed her own children instead of their being killed by other Corinthians after her departure, and whose play Hippolytus, narratively introduced by Aphrodite, Goddess of Love in person, is suspected to have displeased his contemporary audiences because he portrayed Phaedra as too lusty.
In historiography, what is now called speculative fiction has previously been termed "historical invention", "historical fiction", and similar names. It is extensively noted in literary criticism of the works of William Shakespeare as when he co-locates Athenian Duke Theseus and Amazonian Queen Hippolyta, English fairy Puck, and Roman god Cupid across time and space in the Fairyland of its Merovingian Germanic sovereign Oberon in A Midsummer Night's Dream.
In mythography the concept of speculative fiction has been termed "mythopoesis" or mythopoeia, "fictional speculation", the creative design and generation of lore, regarding such works as J. R. R. Tolkien's The Lord of the Rings. Such supernatural, alternate history and sexuality themes continue in works produced within the modern speculative fiction genre.
The creation of speculative fiction in its general sense of hypothetical history, explanation, or ahistorical storytelling has also been attributed to authors in ostensibly non-fiction mode since as early as Herodotus of Halicarnassus (fl. 5th century BCE), in his Histories, and was already both practiced and edited out by early encyclopaedic writers like Sima Qian (ca. 145 or 135 BCE–86 BCE), author of Shiji.
These examples highlight the caveat that many works now regarded as intentional or unintentional speculative fiction long predate the coining of the genre term; its concept in its broadest sense captures both a conscious and unconscious aspect of human psychology in making sense of the world, and responding to it by creating imaginative, inventive, and artistic expressions. Such expressions can contribute to practical progress through interpersonal influences, social and cultural movements, scientific research and advances, and philosophy of science.
In its English-language usage in arts and literature since the mid 20th century, "speculative fiction" as a genre term is often attributed to Robert A. Heinlein. He first used the term in an editorial in The Saturday Evening Post, February 8, 1947. In the article, Heinlein used "Speculative Fiction" as a synonym for "science fiction"; in a later piece, he explicitly stated that his use of the term did not include fantasy. However, though Heinlein may have come up with the term on his own, there are earlier citations: a piece in Lippincott's Monthly Magazine in 1889 used the term in reference to Edward Bellamy's Looking Backward: 2000–1887 and other works; and one in the May 1900 issue of The Bookman said that John Uri Lloyd's Etidorhpa, The End of the Earth had "created a great deal of discussion among people interested in speculative fiction". A variation on this term is "speculative literature".
The use of "speculative fiction" in the sense of expressing dissatisfaction with traditional or establishment science fiction was popularized in the 1960s and early 1970s by Judith Merril and other writers and editors, in connection with the New Wave movement. It fell into disuse around the mid-1970s.
The Internet Speculative Fiction Database contains a broad list of different subtypes.
In the 2000s, the term came into wider use as a convenient collective term for a set of genres. However, some writers, such as Margaret Atwood, continue to distinguish "speculative fiction" specifically as a "no Martians" type of science fiction, "about things that really could happen."
Academic journals which publish essays on speculative fiction include , and Foundation.
According to publisher statistics, men outnumber women about two to one among English-language speculative fiction writers aiming for professional publication. However, the percentages vary considerably by genre, with women outnumbering men in the fields of urban fantasy, paranormal romance and young adult fiction.