Abstract We provide the first quantification of chaotic intrinsic variability (CIV) in the Arctic‐North Atlantic region, using an ensemble of 13 eddy‐permitting ocean–sea ice simulations. By isolating oceanic CIV from atmospheric variability, we show that CIV contributes 20%–60% of sea surface temperature interannual variability in the northern North Atlantic at the Arctic gateways, with a greater influence at subsurface levels. Salinity CIV accounts for 20%–50% of interannual variability, particularly in the Arctic. Furthermore, CIV contributes to a notable portion of sea ice concentration interannual variability in the marginal ice zone, likely influenced by dynamical interactions between sea ice and small‐scale features. CIV is shown to emerge in preferential regions, with its seasonal amplitude modulated by sea ice conditions. Given the potential for CIV to amplify in a warming Arctic, understanding its role in ocean and sea ice variability under changing climate conditions is crucial for improving predictions in this region.