Geophysical data from the UK continental shelf off NW Scotland reveal strongly parallel subglacial bedforms on the sea bed. Field mapping on the adjacent landmass has identified closely spaced bedrock megagrooves and highly elongate drumlinoid forms. All these mega-scale glacial lineations probably formed beneath the same fast-flowing zone of the last British–Irish Ice Sheet, The Minch palaeo-ice stream. This ice stream drained the NW sector of the British–Irish Ice Sheet during the Late Devensian Glaciation (marine isotope stage 2) and terminated near the edge of the continental shelf. The size of the adjacent trough-mouth Sula Sgeir Fan and the presence of buried mega-scale glacial lineations within the Quaternary stratigraphic record imply that fast ice-sheet flow in The Minch has been a feature of several mid- to late Pleistocene glaciations.