The Antarctic coastal marine region is a unique and highly complex environment, of which landfast sea ice and polynyas are key features, especially in the context of dense water formation. Current Earth System Models (ESMs) and their sea ice component hardly simulate any Antarctic landfast ice, which has presumably negative implications on sea ice and polynya dynamics. Here we develop, implement and evaluate the first circumpolar Antarctic landfast-ice representation for large-scale ice-ocean models. This representation is empirical, based on the restoring of sea ice velocity to zero where and when landfast ice is observed, according to a recently released circum-Antarctic landfast ice database. Using 2001-2017 hindcast simulations with the NEMO-SI 3 model, we demonstrate that prescribing landfast ice not only ensures accurate landfast ice coverage, as expected, but also largely improves simulated landfast ice thickness and polynya dynamics. This includes more realistic polynya coverage, individual polynya shape, frequency and ice production rates. Additionally, the model low bias on summer ice extent is reduced, as prescribing landfast ice locks thicker ice near the coast, taking longer to melt. Our simulations also give the first estimate of landfast sea ice volume, which accounts for 10.6 % of the pan-Antarctic total, as compared to 3.8 % for extent. We argue that velocity restoring is appropriate for some investigations of the Antarctic landfast sea ice over the recent past, but not for the remote past or future projections, for which a physical representation of landfast ice drivers, particularly iceberg-sea ice interactions, is necessary.