The region of present-day Angola was one of the main areas from which millions of enslaved Africans were abducted and forced to migrate to the Americas during the transatlantic slave trade. Strontium isotope (⁸⁷Sr/⁸⁶Sr) analysis is a useful tool in reconstructing large-scale human movements across geologically distinct landscapes in archaeological and forensic contexts. However, the absence of environmental ⁸⁷Sr/⁸⁶Sr reference data from Angola hinders the use of ⁸⁷Sr/⁸⁶Sr analysis in provenance studies related to Angola, especially in identifying the geographic origin of enslaved people in the African Diaspora. Here, we measured 101 plant samples from most, yet not all, major geological units to draft the first bioavailable ⁸⁷Sr/⁸⁶Sr map (isoscape) for Angola using a machine learning framework. Our results suggest that the ⁸⁷Sr/⁸⁶Sr ratios in Angola span a large range from 0.70679 to 0.76815 between the different geological units. Specifically, the high average ⁸⁷Sr/⁸⁶Sr ratios of 0.74097 (±0.00938, 1 SD) found in the Angola Block of central Angola, are distinctly more radiogenic than any previously published bioavailable ⁸⁷Sr/⁸⁶Sr ratios for western Central and West Africa. However, these match the ⁸⁷Sr/⁸⁶Sr ratios previously published for human enamel samples from four historic slavery contexts in the Americas. We demonstrate that our strontium isoscape of Angola greatly improves the ability to assess the possible origins of enslaved African individuals discovered outside of Africa and encourage the future use of emerging African isoscapes in the study of life histories within the slave trade.