The dataset comprises of biogeochemical measurements of saltmarsh soil collected from 46 salt marshes across Scotland. Sites were chosen to represent contrasting habitats across Scotland, in particular sediment types, vegetation and sea level history. The data provide a quantitative measure of the dry bulk density, soil texture, organic matter content (LOI) and organic carbon present within surface soils (up to a depth of 10 cm). A total of 471 samples were collected, 157 of the samples were collected using modified syringe samplers as part of the citizen scientist programme CarbonQuest (Part of C-SIDE) these were supplemented by a further 109 samples from the C-SIDE team. The remaining 205 samples were collected using a soil corer (Gouge) as part of the C-SIDE sampling programme. The samples were processed for bulk density, soil texture, organic matter content using the Loss on Ignition (LOI) method and the organic carbon was quantified through elemental analysis. The data were collected to help create a detailed picture of saltmarsh carbon storage across Scotland. The work was carried out under the NERC programme - Carbon Storage in Intertidal Environment (C-SIDE), NERC grant reference NE/R010846/1 Full details about this dataset can be found at https://doi.org/10.5285/81a1301f-e5e2-44f9-afe0-0ea5bb08010f