This dataset contains age-calibrated stable cadmium isotope records covering the 56Ma Palaeocene-Eocene Thermal Maximum (PETM) event, along with supporting molybdenum data and ANOVA (Analysis of Variance) statistics for each record. Samples analysed are mudrocks deposited during the PETM at four locations, Arctic Ocean, Svalbard, Central North Sea and Kheu River, southern Caucasus. Data was collected via bulk sediment digestion, ICP-MS/ICP-OES (concentration) and MC-ICP-MS (isotope) analytical techniques, with detrital correction and elemental enrichment calculations carried out using previously published upper crustal compositional data. These data were collected to independently trace changes in carbon burial trends across the event, using cadmium mass balance and cadmium-carbon relationships to model these changes. These data will be useful to those attempting palaeo-climate reconstructions, investigating climate change- related carbon cycle feedbacks, and developing metal isotope proxies for biogeochemical cycling in general. These data are published in Elms et al., 2026 (currently in review, AGU publications Geochemistry, Geophysics, Geosystems).