The compilation combines measurements of nitrate δ¹⁵N (vs Air N₂) and δ¹⁸O (vs VSMOW) from the global ocean together with ancillary hydrographic and biogeochemical measurements when available, including temperature, salinity, dissolved oxygen, nitrate, nitrite, phosphate, silicate, and ammonium concentrations. The database contains 3410 stations, including 29769 nitrate δ¹⁵N measurements and 26637 nitrate δ¹⁸O measurements. Associated metadata include cruise identifiers, bibliographic references, Digital Object Identifiers (DOIs) linking datasets to the original studies whenever available, latitude, longitude, cruise start and end dates, sampling date, and sampling depth. This compilation also includes most nitrate δ¹⁵N measurements reported in Rafter et al. (2019; n = 12277) and Fripiat et al. (2021; n = 15300), together with an expanded collection of nitrate δ¹⁸O measurements.