<p>The hydrogen and oxygen stable isotope ratios of water have been used to identify sources, transport pathways, and phase-change processes within the water cycle, supporting hydrologic, forensic, ecologic, and hydroclimatic investigations. Here, we introduce an unique, open-access, global database of stable water isotope ratios (<i>δ</i><sup>18</sup>O, <i>δ</i><sup>17</sup>O and <i>δ</i><sup>2</sup>H) from various waters types. This database facilitates data preservation, supports standardized metadata collection, and decreases the time investment for metanalytic research and reference dataset discovery. As of April 2019, the database includes 227 699 samples from 51 321 sites, associated with 207 projects, spanning 1949 through 2019. Key information stored includes the hydrogen and oxygen isotope ratios, water type, collection date and time, site location, and project information. To promote rapid data discovery and collaboration, the database exposes metadata and data owner contact information embargoed data, but only permits downloads of public data. The database is supported by two companion apps, one for processing and upload of analytical data from laboratories and the other an iOS application that supports digital collection of sample metadata.</p>