The Naval Order of the United States (NOUS) was founded in 1890 by Charles Calhoun Philbrook, Charles Frederick Bacon Philbrook, and Franklin Senter Frisbie, as a hereditary organization in the United States for members of the American sea services. Its primary mission is to encourage research and writing on naval and maritime subjects, and to preserve documents, portraits, and other records of prominent figures, deeds, and memories of American naval and maritime history. It is the oldest American hereditary exclusively naval society. Since its founding in Boston, Massachusetts, branches were established over the years in several states, with the Southwest Commandery having been established on October 20, 1981.

The membership criteria for NOUS regular members includes any United States citizen, who has served or is serving as an officer or enlisted member of the United States Navy, U.S. Marine Corps, the U.S. Coast Guard, and any other federal military maritime service of the United States or its allies, and their descendants over 18 years of age who are U.S. citizens. Associate members include spouses of present and deceased regular members, and those, other than United States citizens, who have served or are serving honorably as commissioned officers in an allied seagoing service. Also, the Naval Order may confer either associate or honorary membership upon individuals who are not otherwise eligible for regular or associate membership, if they have distinguished themselves in the interest of naval service.