This dataset includes the multi-proxy analysis of sediment core NBP20-02 KC72, collected from Cranton Bay, a small, biologically productive, and bathymetrically isolated embayment north of Pine Island Glacier in the Amundsen Sea, West Antarctica. The data are used to reconstruct past environmental and oceanographic changes in the bay since the Late Pleistocene and throughout the Holocene. Parameters include magnetic susceptibility, sediment grain size analysis, bulk sediment stable carbon isotopes, and Total Organic Carbon (TOC), as well as counts of diatom species.