Black science fiction or black speculative fiction is an umbrella term that covers a variety of activities within the science fiction, fantasy, and horror genres where people of the African descent take part or are depicted. Some of its defining characteristics include a critique of the social structures leading to black oppression paired with an investment in social change. Black science fiction is "fed by technology but not led by it." This means that black science fiction often explores with human engagement with technology instead of technology as an innate good.

In the late 1990s a number of cultural critics began to use the term Afrofuturism to depict a cultural and literary movement of thinkers and artists of the African diaspora who were using science, technology, and science fiction as means of exploring the black experience. However, as Nisi Shawl describes in her series on the history of black science fiction, black science fiction is a wide-ranging genre with a history reaching as far back as the 19th century. Also, because of the interconnections between black culture and black science fiction, "readers and critics need first to be familiar with the traditions of African American literature and culture" in order to correctly interpret the nuances of the texts. Indeed, John Pfeiffer has argued that there have always been elements of speculative fiction in black literature.

According to Jess Nevins, "a fully accurate history of black speculative fiction ... would be impossible to write" because very little is known of the dime novel authors of the 19th century and the pulp magazine writers of the early 20th century, including notably their ethnicity. Although the concept of science fiction as a discrete genre had already emerged in the late 19th century, its early black exponents do not appear to have been influenced by each other. Moreover, because of the genre of science fiction often prioritizing publication via a set of canonical magazines, it can be difficult to create a timeline for black science fiction because its authors may not have been included in those publications. Hope Wabuke, a writer and assistant professor at the University of Nebraska–Lincoln of English and Creative Writing, argues that the term "Black Speculative Literature" can encompass the terms Afrofuturism, Africanfuturism, and Africanjujuism, the latter two coined by Nnedi Okorafor, all of which center "African and African diasporic culture, thought, mythos, philosophy, and worldviews."

In 1859, Martin Delany (1812–1885), one of the foremost U.S. black political leaders and known as the "father of Black Nationalism," began publishing Blake; or the Huts of America as a serial in The Anglo-African Magazine. Delany, also internationally known as a scientist and explorer, positioned Blake as an engagement with the racial sciences of the time. The Anglo-African Magazine often also published articles on science, particularly the science of race. The subject of Delany's serial novel is a successful slave revolt in the Southern states and the founding of a new black country in Cuba. Samuel R. Delany described it as "about as close to an SF-style alternate history novel as you can get." The serialization ended prematurely, but the entire novel was eventually published in serial form in the Weekly Anglo-African in weekly installments from November 1861 to May 1862.^{[citation needed]}

The Anglo-African was considered the premier publication featuring the work of black scientists and theorists; Blake's inclusion in its serials highlights its connection to a larger political context focused on black citizenship in the antebellum South. Further, while it incorporates elements of the fugitive slave narrative, Blake's narrator is also a scientist, whose focus on data collection and research stand in repudiation of the racial science of the day. In fact, this reflects one of Delany's major themes: that Africa and its contributions to science and math were foundational to the Western world.

In terms of genre, Blake represents an early example of black utopian speculative fiction. In Passing and the African American Novel, Maria Giulia Fabi writes, "Less convinced of the libratory potential of technological progress than their white counterparts, African American utopian writers focused on the process of individual and collective ideological change rather than on the accomplished perfection of utopia itself." It is also a proto-Afrofuturist novel. Lisa Yaszek writes, "[I]n a move that would set the tone for nearly a century of Afrofuturist SF to come," Delany explores the ambivalence and precarity of black cultural survival while simultaneously arguing for black technological prowess. Further, because of Delany's interest in black separatism and the establishment of a black state, Blake is an extension and exploration of the themes and ideas he explored in his 1852 publication of The Condition, Elevation, Emigration, and Destiny of the Colored People of the United States. Blake was never published as a complete, stand-alone novel in the nineteenth century.

Charles W. Chesnutt (1858–1932) was a noted writer of folkloric hoodoo stories. His collection The Conjure Woman (1899) is the first known speculative fiction collection written by a person of color. The 1892 novel Iola Leroy by Frances Harper (1825–1911), the leading black woman poet of the 19th century, has been described as the first piece of African-American utopian fiction on account of its vision of a peaceful and equal polity of men and women, whites and former slaves. In contrast, the 1899 novel Imperium in Imperio by Sutton Griggs (1872–1933) ends with preparations for a violent takeover of Texas for African Americans by a secret black government. Imperium in Imperio is credited with being the first political novel written by an African American. Griggs self-published his novel and sold it door-to-door.

Of One Blood (1902) by the prolific writer and editor Pauline Hopkins (1859–1930), describing the discovery of a hidden civilization with advanced technology in Ethiopia, is the first "lost race" novel by an African-American author. However, unlike other entrants into this genre, Hopkins' "lost race" offers a homecoming to her black protagonists. Light Ahead for the Negro, a 1904 novel by Edward A. Johnson (1860–1944), is an early attempt at imagining a realistic post-racist American society, describing how by 2006 Negroes are encouraged to read books and given land by the government. W. E. B. Du Bois's 1920 story The Comet, in which only a black man and a white woman survive an apocalyptic event, is the first work of post-apocalyptic fiction in which African Americans appear as subjects. George Schuyler (1895–1977), the noted conservative U.S. critic and writer, published several works of speculative fiction in the 1930s, using the framework of pulp fiction to explore racial conflict. Published in The Pittsburgh Courier, Schuyler's serials lampoon the Talented Tenth, criticize colorism, and explore double-consciousness.