The dataset contains geochemical and isotopic data used for the characterisation of the organic matter (OM) present in a sediment core retrieved from the Bay of Biscay (core GeoB23302-2). This includes n-alkane concentrations, values for the branched and isoprenoid tetraether (BIT) index, and the fractional abundance of hopanes (fββ), at various depths of the sedimentary archive. The X-ray fluorescence (XRF) analysis of core GeoB23302-2 returned values for the ratios Fe/Ca and Zr/Rb, which are given in the dataset. Radiocarbon and stable carbon isotopes (bulk OM) and compound-specific radiocarbon data (n-alkanoic acids) are also present in the data file. The age-depth model of core GeoB23302-2 was constructed based on seven radiocarbon accelerator mass spectrometry measurements of planktic foraminifera, which are also reported.