This dataset reports authigenic neodymium isotope composition (143Nd/144Nd, expressed as εNd) extracted from iron–manganese oxyhydroxide coatings in bulk marine sediments at Ocean Drilling Program (ODP) Site 162-982 on the Rockall Plateau, North Atlantic. The record spans the past approximately 230 ka, covering two glacial–interglacial cycles. A reductive leaching procedure using hydroxylamine hydrochloride was applied to selectively dissolve the authigenic iron–manganese oxyhydroxide phase, preserving the bottom-water neodymium isotope signal. Isotope composition were measured on a Thermo Fisher Scientific Neptune Plus multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS) at the Institute of Environmental Physics, Heidelberg University. The data are used to reconstruct changes in intermediate water mass provenance in the North Atlantic across glacial–interglacial cycles and to investigate the role of ice-sheet dynamics in driving these shifts.