| MSCI | business, public company | New York City | 1969 |
| MTV Entertainment Studios | film production company | Hollywood | 1991 |
| Museum of Fine Arts, Houston | production company, nonprofit organization, art museum, museum | Houston | 1900 |
| Museum of Modern Art | production company, nonprofit organization, art museum, museum building, museum, museum of modern art | New York City | 1929 |
| MyFreeCams | adult camming website | — | March 19, 2002 |
| Namesys | business | Oakland | 2004 |
| Naropa University | private not-for-profit educational institution, university | — | 1974 |
| NASA Space Science Data Coordinated Archive | data library | — | 1966 |
| National Academies of Sciences, Engineering, and Medicine | scientific organization, national academy, academy of sciences | Washington, D.C. | 1863 |
| National Academy of Engineering | academy of sciences | Washington, D.C. | 1964 |
| National Amusements | cinema chain | Norwood | 1936 |
| National Basketball Association | basketball association, professional sports league, basketball league, online database | — | August 3, 1949 |
| National Bureau of Economic Research | nonprofit organization, publishing house, research institute | Cambridge | 1920 |
| National Catholic Reporter | newspaper, publishing house | Kansas City | 1964 |
| National Defense University | national defense university, staff college | — | 1976 |
| National Fire Protection Association | production company, standards organization, nonprofit organization | Quincy | 1896 |
| National Football League | American football league, professional sports league | 345 Park Avenue | 1920 |
| National Gallery of Art | nonprofit organization, publishing house, United States federal agency, public–private partnership, national gallery | Washington, D.C. | March 24, 1937 |
| National Geographic Partners | publishing house, business, enterprise, company | New York City | September 9, 2015 |
| National Geographic Society | nonprofit organization, film production company, publishing house, scientific society | Washington, D.C. | 1888 |
| National Hockey League | professional sports league, ice hockey league | New York City | November 26, 1917 |
| National Instruments | business, enterprise, public company | Austin | 1976 |
| National Research Council | academy of sciences | — | June 19, 1916 |
| National War College | staff college, military school | Fort Lesley J. McNair | 1946 |
| National Wrestling Alliance | business, enterprise, professional wrestling promotion | Houston | 1948 |
| Nationwide Mutual Insurance Company | insurance company, business | One Nationwide Plaza | 1926 |
| Nature Portfolio | publishing house, open-access publisher, academic publisher | London | 1999 |
| Naughty America | pornographic film distributor, pornographic film studio | San Diego | 2001 |
| Naughty Dog | video game developer | Santa Monica | 1984 |
| Nautica | brand, business | New York City | 1983 |
| Naval History & Heritage Command | archives, command, museum, library | Washington Navy Yard | 1944 |
| Naval Postgraduate School | naval force university, staff college, public educational institution of the United States, open-access publisher | — | 1909 |
| NBC | radio network, production company, television network | NBC Tower, 10 Universal City Plaza, Stamford, 30 Rockefeller Plaza | 1939 |
| NBC News | production company, online newspaper, television channel, specialty channel | New York City, 30 Rockefeller Plaza | February 21, 1940 |
| NCR Corporation | business, enterprise, public company | Atlanta, Augsburg | 1884 |
| Neiman Marcus | business | Dallas | 1907 |
| NetApp | business, enterprise, public company | Sunnyvale | 1992 |
| Netflix, Inc. | television production company, film distributor, business, enterprise, public company | Los Gatos | August 29, 1997 |
| NetherRealm Studios | video game developer | Chicago | 2010 |
| NetJets | airline, business | Columbus | 1964 |
| Netlify | business | San Francisco | January 27, 2014 |
| NetSuite | business, enterprise, public company | Austin | 1998 |
| New Amsterdam Theatre | Broadway theatre, theatre building, movie theater | — | 1903 |
| New College of Florida | liberal arts college, Colleges That Change Lives, public educational institution of the United States | — | 1960 |
| New England Conservatory | conservatory, university building, private not-for-profit educational institution, college of music | — | 1867 |
| New Frontier Hotel and Casino | casino, destroyed building or structure, hotel, music venue | — | 1942 |
| New Mexico State University | public educational institution of the United States, open-access publisher, land-grant university, public university | University Park | 1888 |
| New World Computing | video game developer | Agoura Hills | 1984 |