MiCoDa is a searchable database that hosts over 30,000 samples of processed 16S rRNA gene amplicon sequences from aquatic, host-associated, and mineral environments, spanning the entire globe. To improve cross-study comparability, all samples in MiCoDa have been sequenced in the same region of the 16S rRNA gene (between base pairs 515 and 806). MiCoDa also hosts the Earth Microbiome Project samples, processed in the same manner. MiCoDa is currently the largest public, human-curated microbiome database available. Its goal is to encourage the reuse of extant sequence data by specialists and non-specialists alike. To this end, we have manually curated the data and metadata included, preprocessed the sequence data to maximize comparability, and created a searchable data portal. MiCoDa is led by Dr. Stephanie Jurburg (microbial ecology), and hosted and supported by the Integrative Biodiversity Data and Code Unit of the German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, the Microbial Interaction Ecology group of the Helmholtz Centre for Environmental Research- Leipzig and the FUSION group of Friedrich Schiller Universität- Jena. For more information about MiCoDA and the Data Collection, visit https://micoda.idiv.de/v1/dataCollection [This dataset was processed using the GBIF Metabarcoding Data Toolkit.]