For more than 25 years, the U.S. Geological Survey Gas Hydrates Project has compiled and maintained an internal database of locations where the existence of gas hydrate has been confirmed or inferred in research studies. The existence of gas hydrate was considered confirmed when gas hydrate was recovered by researchers or videotaped from a vehicle (such as a submersible or remotely operated vehicle) near the sea floor. The existence of gas hydrate was considered inferred when seismic data, borehole logs, or certain geochemical characteristics match anomalies known to characterize gas hydrate. This data release provides a text description of the region, geographic coordinates, and the citation for the published reference for known and inferred gas hydrate locations. Where the existence of gas hydrate was inferred, the description of the criteria used to make the inference was also included. Additional notes are provided to address any inconsistencies in the original locations (e.g., swapped latitude and longitude coordinates).