Abstract The Southern Ocean plays a vital role in mitigating global warming through its uptake of anthropogenic carbon ( C ant ). Because of its dynamic nature, the Southern Ocean circulation is challenging to accurately simulate with today’s Earth system models (ESMs), which often have insufficient resolution to resolve small but important mesoscale processes. Here, we assess how the modeled Southern Ocean C ant uptake and storage are affected by the explicit simulation of mesoscale eddies. Specifically, we compare a global ocean biogeochemistry simulation having eddy-rich resolution (0.1°) in the Southern Ocean with a 0.5° simulation where eddy effects are parameterized. We find that explicitly simulating Southern Ocean mesoscale eddies enhances Southern Ocean C ant uptake by 10% and the global C ant interior storage by 8%. Steeper—and more realistic—density slopes in the eddy-rich model facilitate the upward transport of deep waters, yielding enhanced C ant uptake via various processes: lower surface C ant concentrations, elevated surface salinity, increased vertical mixing, and higher chemical carbon uptake capacity. Explicitly simulating eddies enhances C ant inventories in both bottom and mode/intermediate waters but with a 30% shift toward bottom waters, which could potentially affect the long-term sequestration of C ant . These findings, consistent across an additional model family, help reconcile discrepancies between observations and ESMs, which often underestimate the Southern Ocean C ant uptake. This study emphasizes the need for adequate model resolution, or improved eddy parameterizations, to accurately simulate the global carbon cycle and to reduce uncertainties in future climate projections informing climate policy. Significance Statement The Southern Ocean plays a vital role in mitigating global warming through its uptake of anthropogenic carbon. However, this process remains poorly constrained in Earth system models, which often have a resolution insufficient to simulate small but important ocean features like mesoscale eddies. This study explores whether high-resolution ocean models, which capture these eddies, differ in their absorption of anthropogenic carbon in the Southern Ocean. We find that higher-resolution models take up and store around 10% more anthropogenic carbon in the Southern Ocean with respect to lower-resolution ones, owing to a circulation better matched to observations. These findings help reconcile discrepancies between models and observations and suggest that many low-resolution Earth system models may underestimate Southern Ocean anthropogenic carbon storage, potentially biasing projections toward higher levels of global warming.