This dataset contains raw and processed physicochemical characterization data for biocarbons produced from four distinct biomass waste feedstocks: coconut shell (CS), switchgrass (SG), rice husk (RH), and shrimp shell (SS). Biocarbons were produced by pyrolysis and characterized to establish feedstock–property relationships. The data support comparative analysis of feedstock-dependent structure–property relationships in biocarbon materials, including ash content, thermal stability, elemental composition, morphology, particle size distribution, functional group chemistry, carbon structural order, crystallinity, and electrical conductivity. The dataset includes native instrument output files, processed analysis files, and final figure files corresponding directly to figures reported in the associated peer-reviewed manuscript. These data are intended to enable reproducibility, secondary analysis, and educational reuse in the field of sustainable materials and biomass valorization.