This dataset contains multiproxy palaeoceanographic records from the northern Bay of Bengal covering the Late Pliocene to Early Pleistocene (~3.5–2.3 Ma). Data include X-ray fluorescence (XRF) elemental records, age-depth tie points, benthic foraminiferal δ¹⁸O, diatom assemblages, and planktic foraminiferal relative abundances. The dataset supports interpretations of monsoon-induced runoff and changes in marine biological productivity and their relationship with orbital forcing. The data were collected from IODP Site U1445 and analysed in support of the study "Influence of Indian Summer Monsoon on Marine Biological Productivity Across the Late Pliocene and Early Pleistocene.