The Antarctic Ice Sheet (AIS) response to past warming consistent with the 1.5–2°C ‘safe limit’ of the United Nations Paris Agreement is currently not well known. Empirical evidence from the most recent comparable period, the Last Interglaciation, is sparse, and transient ice-sheet model simulations are few and inconsistent. Here we present new results from transiently-forced ice-sheet modelling experiments. We evaluate our results against near and far-field proxy reconstructions and find good agreement. Our simulations indicate that the AIS contributed approximately 4 m to global mean sea level, peaking at 126 ka BP, with ice lost primarily from the Amundsen but not Ross or Weddell Sea sectors. The AIS thinned in the area of the Wilkes Subglacial Basin but did not retreat. Continuing beyond present day our model predicts that the West Antarctic Ice Sheet may already be predisposed to collapse even in the absence of further environmental change.