Pollen, plant macrofossil, charcoal, geochronological, and loss-on-ignition data from sediment core GDS-520-03-21-2017 were generated in support of research on long-term patterns of vegetation, fire, and climate in Great Dismal Swamp National Wildlife Refuge (Willard et al., in review). Raw counts of pollen data are provided. Plant macrofossil data are presented as percentages for herbaceous, ligneous, and undifferentiated plant macrofossils and presence/absence data for specific plant taxa. Macroscopic charcoal was counted in three size classes: 125-250 micrometers, and 250-500 micrometers, and >500 micrometers. Uncalibrated radiocarbon dates were obtained and provided for use in development of age models for analyses by Willard et al, in review. Loss-on-ignition data are presented as percent organic matter.