The Black Seminoles (Spanish: Semínolas Negros), or Afro-Seminoles (Afro-Seminolas), are an ethnic group of mixed Seminole and African origin. They are mostly blood descendants of the Seminole people, free Africans, and escaped former slaves, who allied with Seminole groups in Spanish Florida. Their history includes a continuous struggle against invasion and enslavement while preserving their distinct culture and reconnecting with their relatives throughout the African diaspora. Many have Seminole lineage, but due to the stigma of having mixed origin, they have all been categorized as slaves or Freedmen in the past.

Historically, the Black Seminoles lived mostly in distinct bands near the Native American Seminoles. Some were held as slaves, particularly of Seminole leaders, but the Black Seminole had more freedom than did slaves held by whites in the South and by other Native American tribes. This included the use of firearms. Today, Black Seminole descendants live primarily in rural communities around the Seminole Nation of Oklahoma. Its two Freedmen's bands, the Caesar Bruner Band and the Dosar Barkus Band, are represented on the General Council of the Nation. Other centers are in Florida, Texas, the Bahamas, and northern Mexico. Their culture is a blending of African, Gullah, Seminole, Mexican, Caribbean, and European traditions.

Since the 1930s, the Seminole Freedmen have struggled with cycles of exclusion from the Seminole Nation of Oklahoma. In 1990, the tribe received the majority of a $56 million judgment trust by the United States, for seizure of lands in Florida in 1823, and the Freedmen have worked to gain a share of it. In 1999, the Seminole Freedmen's suit against the government was dismissed in the United States Court of Appeals for the Tenth Circuit; the court ruled the Freedmen could not bring suit independently of the Seminole Nation of Oklahoma, which refused to join on the claim issue.

In 2000 the Seminole Nation voted to restrict membership to those who could prove descent from a Seminole on the Dawes Rolls of the early 20th century, which excluded about 1,200 Freedmen who were previously included as members. Excluded Freedmen argue that the Dawes Rolls were inaccurate and often classified persons with both Seminole and African ancestry as only Freedmen. The District Court for the District of Columbia however ruled in Seminole Nation of Oklahoma v. Norton that Freedmen retained membership and voting rights.

Spaniards were the first Europeans to colonize Florida and North America in the 16th century. The colony of Spanish Florida included Georgia, the Carolinas, Mississippi, and Alabama. Prior to colonization, Native Americans lived on the land for thousands of years where they hunted, fished, raised cattle, and performed religious ceremonies. Over time, European contact affected Indigenous peoples' way of life. Indigenous peoples in Spanish Florida defended their lands from European settlers and colonists. By the 17th century, Spaniards lacked the resources to protect all of Florida's territory. Spain lost control of the Carolinas in 1633 and the Georgia colony in 1670 to the English (British).

To escape conflict with Europeans, Muscogee people from Alabama and Georgia fled to Florida in search of new lands. Over time the Creek (Muscogee) were joined by other remnant groups of Southeast American Native Americans, such as the Miccosukee, Choctaw, and the Apalachicola, and formed communities. Other Native American tribes, the Yuchis and Yamasees, merged with the Muscogee and by a process of ethnogenesis, the Native Americans formed the Seminole. Spain had given land to some Muscogee (Creek) Native Americans. Their community evolved over the late 18th and early 19th centuries as waves of Creek left present-day Georgia and Alabama under pressure from white settlement and the Creek Wars. In 1773, when the American naturalist William Bartram visited the area, he referred to the Seminole as a distinct people. He believed their name was derived from the word "simanó-li", which according to John Reed Swanton, "is applied by the Creeks to people who remove from populous towns and live by themselves."

William C. Sturtevant says the ethnonym was borrowed by Muskogee from the Spanish word cimarrón, supposedly the source as well of the English word maroon. This was used to describe the runaway slave communities of Florida and of the Great Dismal Swamp on the border of Virginia and North Carolina, on colonial islands of the Caribbean, and other parts of the New World. But linguist Leo Spitzer, writing in the journal Language, says, "If there is a connection between Eng. maroon, Fr. marron, and Sp. cimarron, Spain (or Spanish America) probably gave the word directly to England (or English America)."

Enslaved and free Africans in the Sea Islands of South Carolina and Georgia gradually formed what has become known as the Gullah culture of the coastal Southeast that will influence Black Seminole culture. As early as 1686, enslaved people from the Carolinas, Georgia, and the Sea Islands fled British plantations on the Underground Railroad, finding refuge and alliance with Florida's Indigenous populations. These freedom seekers became known as the "Black Seminoles" and "Seminole Maroons". Under a 1693 edict from King Charles II of Spain, freedom seekers received liberty in exchange for defending the Spanish settlers at St. Augustine against the British. The Spanish organized the Black volunteers into a militia; their settlement at Fort Mosé, founded in 1738, was the first legally sanctioned free Black town in North America. In 1739, Carolinas slaveholders complained to Governor Manuel de Mantiano of Spanish Florida about enslaved laborers escaping to Spanish territory. Mantiano upheld the right to sanctuary, established in Spanish law, for formerly enslaved people seeking freedom.