Geometries of Early Pleistocene (2.58–0.78 million years ago) ice sheets in NW Europe are poorly constrained, but are required to improve our understanding of past ocean-atmosphere-cryosphere coupling. Ice sheets are believed to have changed in their response to orbital forcing, becoming, from about 1.2 million years ago, volumetrically larger, and longer-lived. Here, we present a multi-proxy dataset for the North Sea, extending to over a kilometre below the present-day seafloor, which clearly demonstrates spatially extensive glaciation of the basin from the earliest Pleistocene. Ice sheets repeatedly entered the North Sea, south of 60°N, in water depths of up to ~250 m from 2.53 Ma and subsequently grounded in the centre of the basin, in deeper water, from 1.87 Ma. Despite lower global ice volumes, these ice sheets were near-comparable in spatial extent to those of the Middle and Late Pleistocene but possibly thinner and moving over slippery (low basal resistance) beds.