Abstract Antarctic marginal seas are crucial for the global climate, but direct observations, especially of mesoscale ocean eddies, remain scarce. Here, by analyzing the unprecedented high-resolution sea surface height data provided by the recently launched Surface Water and Ocean Topography (SWOT) satellite, we reveal for the first time a widespread presence of mesoscale eddies across the Antarctic continental shelf. The geographic distributions of the observed eddies, along with eddy-resolving model simulations, support the hypothesis that ice shelf basal melting and dense shelf water formation are key processes driving the prevalent eddy activity. Our findings highlight the potential of innovative satellite measurements for monitoring critical Antarctic oceanic processes, and the need to resolve the abundant Antarctic ocean eddies in climate models.