This is the list of NATO country codes. Up to and including the seventh edition of STANAG 1059, these were two-letter codes (digrams). The eighth edition, promulgated February 19, 2004 and effective April 1, 2004, replaced all codes with new ones based on the ISO 3166-1 alpha-2 codes. Additional codes cover gaps in the ISO coverage, deal with the imaginary countries used for exercise purposes, and designate large geographical groupings and water bodies (ranging from oceans to rivers). It consists of two-letter codes for geographical entities, four-letter codes for subdivisions, and lists the ISO three-letter codes for reference. The digrams match the FIPS 10-4 codes with a few exceptions.

The ninth edition's ratification draft was published on July 6, 2005 with a reply deadline of October 6, 2005. It replaces all two- and four-letter codes with ISO or ISO-like three- and six-letter codes. It is intended as a transitional standard: once all NATO nations have updated their information systems, a tenth edition will be published.