Mercury (Hg) concentrations and isotope compositions preserved in sedimentary successions provide important information for investigating long-term Hg cycling, volcanism, environmental perturbations, and Earth-system evolution. During the past decade, the rapid expansion of sedimentary Hg research has generated a large volume of concentration and isotope data. However, these data remain dispersed across individual studies and are reported using heterogeneous stratigraphic frameworks, metadata conventions, and analytical formats, limiting their accessibility and large-scale reuse. Here we present DeepSedHg (Deep-time Sedimentary Mercury Concentrations and Isotope Compositions) database, a comprehensive global compilation of published sedimentary Hg concentrations and isotope records spanning approximately 2.7 billion years of Earth history. DeepSedHg version 1.0 integrates data from 199 peer-reviewed publications published between 2010 and February 2026 and contains 28264 sample-level records. The database includes 27,990 Hg measurements, of which 3,736 contain both concentration and isotope data. Each record is accompanied by standardized metadata describing stratigraphy, numerical age, lithology, depositional environment, geographic location, paleogeographic position, and associated geochemical parameters. All records were subjected to systematic data harmonization and quality-control procedures, including duplicate screening, metadata verification, chronostratigraphic standardization, coordinate validation, and consistency checks of geochemical variables. The resulting database provides broad temporal, spatial, and environmental coverage of sedimentary Hg records and is distributed in a machine-readable format together with comprehensive metadata documentation.<strong> </strong>DeepSedHg<strong> </strong>is publicly available through Zenodo (<a href="https://doi.org/10.5281/zenodo.20713398">https://doi.org/10.5281/zenodo.20713398</a>) and an online tool (<a href="https://deepsedhg.pages.dev">https://deepsedhg.pages.dev</a>, which is intended to support future synthesis studies, meta-analyses, data-driven investigations, and interdisciplinary research on Hg cycling and environmental change throughout Earth history.