This dataset consists of total carbon (Ctot), total nitrogen (Ntot), total organic carbon (Corg) and δ13C (organic carbon, δ13Corg) measurements of mid-Pliocene sediments from the Integrated Ocean Drilling Program (IODP) expedition 374, site U1524, in the Ross Sea, Antarctica.Total carbon, total nitrogen and organic carbon were measured in an Elementar Vario Micro Cube elemental analyzer. δ13Corg measurements were performed with an IsoPrime 100 isotope ratio mass spectrometer coupled to an Elementar Vario Isotope Cube elemental analyser in continuous flow mode. For organic carbon (Corg) and δ13Corg measurements, carbonate removal was performed by acid fumigation with HCl.The samples were freeze-dried and homogenized using an agate mortar prior to analysis. However, since different aliquots were used for total carbon and organic carbon measurements, some samples occasionally show slightly higher Corg values than Ctot. Uncertainties were estimated according to Hélie and Hillaire-Marcel (2021).