West African populations carry 2-19% genetic ancestry from archaic ghost population. Archaic lineage diverged before Neanderthals split from modern humans. Site frequency spectra confirm introgression in four West African groups. Genome-wide maps identify archaic segments in Yoruba and Mende without reference genomes. Archaic segments occur at high frequency suggesting adaptive introgression. Ghost archaic substantially shapes present-day West African gene pools. Non-Africans have Neanderthal-Denisovan admixture while West Africans have distinct deep ghost archaic admixture.