This U.S. Geological Survey (USGS) data release provides the descriptions of 11 U.S. sites that include mineral regions, mines, and mineral occurrences that contain enrichments of niobium (Nb). To be included in this data release, a site must have a contained resource and (or) past production of Nb metal greater than 10,000 metric tons, which was the approximate consumption of Nb in the U.S. in 2019 (U.S. Geological Survey, 2020). Sites in this dataset occur in Alaska, Arkansas, Colorado, Nebraska, and Texas. Niobium primarily occurs in oxide minerals of the pyrochlore group, which are most commonly found in carbonatites and alkaline granite-syenite complexes. Globally, the largest Nb deposits occur in Brazil and Canada. In Brazil, the Barreiro carbonatite complex hosts the Araxá deposit that contains more than 460 million metric tons of ore with an average grade of 2.48 percent Nb2O5 (Schulz and others, 2017). The world’s leading producer of Nb outside of Brazil is the Niobec Mine in Quebec, Canada. The Niobec deposit occurs in the Saint-Honoré carbonatite complex, where pyrochlore is the main niobium-bearing mineral; the ore body contains more than 400 million metric tons with an average grade of 0.42 percent Nb2O5 (Schulz and others, 2017). In comparison, the largest known Nb deposit in the U.S. is the Iron Hill deposit in Colorado, which has been prospected for titanium, Nb, rare earth elements and thorium. There are no current U.S. producers of Nb, but the Elk Creek project in Nebraska is in the furthest stage of development. If Elk Creek comes online, it will be the first recorded producer of Nb in the U.S. since the 1950s. Niobium is necessary for strategic, consumer, and commercial applications. The primary use for Nb is for the production of high strength steel alloys used in pipelines, transportation infrastructure, and structural applications (Schulz and others, 2017). As of 2019, the U.S. maintains a history of being 100 percent net import reliant on Nb from countries, such as Brazil and Canada. Niobium is imported to the U.S. as Nb minerals, oxides, and ferroniobium (U.S. Geological Survey, 2020). The entries and descriptions in the database were derived from published papers, reports, data, and internet documents representing a variety of sources, including geologic and exploration studies described in State, Federal, and industry reports. Resources extracted from older sources might not be compliant with current rules and guidelines in minerals industry standards, such as National Instrument 43-101 (NI 43-101). The inclusion of a Nb mineral deposit in this database is not meant to imply that the deposit is currently economic. Rather, these deposits were included to capture the characteristics of the largest Nb deposits in the United States. Inclusion of material in the database is for descriptive purposes only and does not imply endorsement by the U.S. Government. The authors welcome additional published information in order to continually update and refine this dataset. Schulz, K.J., Piatak, N.M., and Papp, J.F., 2017, Niobium and tantalum, chap. M of Schulz, K.J., DeYoung, J.H., Jr., Seal, R.R., II, and Bradley, D.C., eds., Critical mineral resources of the United States—Economic and environmental geology and prospects for future supply: U.S. Geological Survey Professional Paper 1802, p. M1–M34, https://doi.org/10.3133/pp1802M. U.S. Geological Survey, 2020, Mineral commodity summaries 2020: U.S. Geological Survey, 200 p., https://doi.org/10.3133/mcs2020.