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Abstract. Biogeochemical cycling in the semi-enclosed Arctic Ocean is stronglyinfluenced by land–ocean transport of carbon and other elements and isvulnerable to environmental and climate changes. Sediments of the ArcticOcean are an important part of biogeochemical cycling in the Arctic andprovide the opportunity to study present and historical input and the fate oforganic matter (e.g., through permafrost thawing). Comprehensive sedimentary records are required to compare differencesbetween the Arctic regions and to study Arctic biogeochemical budgets. Tothis end, the Circum-Arctic Sediment CArbon DatabasE (CASCADE) wasestablished to curate data primarily on concentrations of organic carbon(OC) and OC isotopes (δ13C, Δ14C) yet also ontotal N (TN) as well as terrigenous biomarkers and other sedimentgeochemical and physical properties. This new database builds on thepublished literature and earlier unpublished records through an extensiveinternational community collaboration. This paper describes the establishment, structure and current status ofCASCADE. The first public version includes OC concentrations in surfacesediments at 4244 oceanographic stations including 2317 with TNconcentrations, 1555 with δ13C-OC values and 268 with Δ14C-OC values and 653 records with quantified terrigenous biomarkers(high-molecular-weight n-alkanes, n-alkanoic acids and lignin phenols).CASCADE also includes data from 326 sediment cores, retrieved by shallowbox or multi-coring, deep gravity/piston coring, or sea-bottom drilling.The comprehensive dataset reveals large-scale features of both OC contentand OC sources between the shelf sea recipients. This offers insight intorelease of pre-aged terrigenous OC to the East Siberian Arctic shelf andyounger terrigenous OC to the Kara Sea. Circum-Arctic sediments therebyreveal patterns of terrestrial OC remobilization and provide clues about thawing of permafrost. CASCADE enables synoptic analysis of OC in Arctic Ocean sediments andfacilitates a wide array of future empirical and modeling studies of theArctic carbon cycle. The database is openly and freely available online(https://doi.org/10.17043/cascade; Martens et al., 2021), is provided in variousmachine-readable data formats (data tables, GIS shapefile, GIS raster), andalso provides ways for contributing data for future CASCADE versions. Wewill continuously update CASCADE with newly published and contributed dataover the foreseeable future as part of the database management of the BolinCentre for Climate Research at Stockholm University.