Windblown mineral dust is a nutrient source to the ocean, influencing global ocean productivity, ocean carbon uptake and climate. In this Review, we examine how dust emission fluxes, sources and compositions have changed over the past 7 Myr and consider the implications for ocean productivity. Since the Late Cenozoic, global cooling and orogenic uplift have enhanced dust emissions from major source regions and fluxes to downwind ocean basins, with the associated nutrient supply varying with dust origin. Glacially derived Asian dust contains higher concentrations of ferrous iron (typically exceeding 30% of the total iron) and phosphorus than the aged, highly oxidized mineral dust from North Africa, which has negligible ferrous iron content. Indeed, Asian dust has a notable influence on Pacific Ocean productivity and, potentially, climate. For example, Middle Pleistocene increases in the content of Asian dust Fe2+ (~45%) and P (~55%) coincided with a threefold to fivefold rise in glacial productivity in the South China Sea and a concurrent shift in phytoplankton ecology in the lower-latitude North Pacific. Therefore, decreasing glaciogenic dust–nutrient supply under continued global warming could notably impact ocean productivity, especially in the Pacific Ocean. Future research should focus on constraining the composition and bioavailability of dust-derived nutrients across a wide range of globally important dust sources so that dust composition and related feedbacks can be better parameterized in Earth system models.