This dataset compiles radiocarbon (14C) dates obtained from soil and lake sediment samples collected at Bylot Island, Nunavut. Bulk soil/sediment samples and, when present, fossil organic fragments (peat/wood) were extracted and dried. Samples were pre-treated (HCl-NaOH-HCl) and combusted to CO2 at the Radiocarbon Dating Laboratory (Université Laval, Québec QC, Canada) and 14C dated by accelerator mass spectrometry (AMS) at Keck Carbon Cycle AMS Facility (University of California, Irvine CA, USA). Radiocarbon dates are reported using Libby’s half-life (5568 yr), corrected for natural fractionation (d13C = -25 ‰ PDB).