Marine invasive species (MIS) can cause irreparable change in new environments, though only 1 in 10 invasive species cause negative impacts to recipient ecosystems. Knowledge of which invasive species could have negative impacts helps ensure that limited resources available for MIS monitoring and management are deployed most effectively. This is particularly true in areas that are difficult to access, such as the Southern Ocean. We used an ensemble ecosystem model to explore the impact of potential future invasions by seven groups of marine invasive species on an Antarctic coastal marine food web. Although most simulations showed native species abundances only changed within 10% of the initial abundance, the establishment of a MIS could plausibly cause significant abundance declines to all native species. This analysis helps us to better understand the potential range of impacts on native species and aid the development of strategies to help prevent or manage their introduction.