Sierra Leone first became inhabited by indigenous African peoples at least 2,500 years ago. The Limba were the first tribe known to inhabit Sierra Leone. The dense tropical rainforest partially isolated the region from other West African cultures, and it became a refuge for peoples escaping violence and jihads. Sierra Leone was named by Portuguese explorer Pedro de Sintra, who mapped the region in 1462. The Freetown estuary provided a good natural harbour for ships to shelter and replenish drinking water, and gained more international attention as coastal and trans-Atlantic trade supplanted trans-Saharan trade.

The Nova Scotian Settlers, or Sierra Leone Settlers, were African Americans who founded the settlement of Freetown, Sierra Leone and the Colony of Sierra Leone, on March 11, 1792. The majority of these black American immigrants were among 3,000 African Americans, mostly former slaves, who had sought freedom and refuge with the British during the American Revolutionary War, leaving rebel masters. They became known as the Black Loyalists. The Nova Scotian Settlers were jointly led by African American Thomas Peters, a former soldier, and English abolitionist John Clarkson. For most of the 19th century, the Settlers resided in Settler Town and remained a distinct ethnic group within the Freetown territory, tending to marry among themselves and with Europeans in the colony.