Mantle plume events are increasingly implicated as the source of gold (Au) in regions of the Earth that show a high Au endowment. However, the process of enriching oceanic crust in Au by plume activity is poorly understood and unconstrained. We present the first systematic study of Au concentrations in oceanic basalts as a function of distance from a plume center. We show that the influence of the Iceland plume on the Mid-Atlantic Ridge progressively enriches the oceanic crust in Au along the Reykjanes Ridge by as much as 13 times normal levels, over a distance of ∼600 km, and that the enrichment can be attributed to specific plume components. This Au enrichment by the Iceland plume implies a genetic relationship between deep mantle upwelling and major gold mineralization.