| National Association for Stock Car Auto Racing | Charlotte | 1948 |
| National Association of Underwater Instructors | Flórida | 1959 |
| National Instruments | Austin | 1976 |
| National Oilwell Varco | Houston | 1862 |
| National Semiconductor | Santa Clara | 1959 |
| National Wrestling Alliance | Houston | 1948 |
| Nationwide Mutual Insurance Company | One Nationwide Plaza | 1926 |
| NCR | Atlanta, Augsburgo | 1884 |
| Neiman Marcus | Dallas | 1907 |
| NetApp | Sunnyvale | 1992 |
| Netgear | São José, Dover | 1996 |
| Neuberger Berman | Nova Iorque | 1939 |
| New Balance | Boston | 1906 |
| Newmont Mining Corporation | Denver | 1916 |
| News Corp | Nova Iorque | 28 de junho de 2013 |
| NeXT | Palo Alto, Redwood City | 20 de junho de 1985 |
| NextEra Energy | Juno Beach | 1925 |
| Nielsen Company | Nova Iorque | 1994 |
| Nik Software | San Diego | 1995 |
| Noble Energy | Houston | 1932 |
| Nordstrom | Seattle | 1901 |
| North American Arms | Provo | 1972 |
| Northern Pacific Railway | Saint Paul | 2 de julho de 1864 |
| Northern Trust | Illinois, Chicago | 1889 |
| Northrop Corporation | Hawthorne | 1939 |
| Norwegian Cruise Line | Condado de Miami-Dade | 1966 |
| Nutanix | São José | 2009 |
| Nvidia | Santa Clara | 5 de abril de 1993 |
| O.F. Mossberg & Sons | North Haven | 1919 |
| Oakley, Inc. | Foothill Ranch | 1975 |
| Oberheim Electronics | Oakland | 1969 |
| Obsidian Entertainment | Irvine | 12 de junho de 2003 |
| Occidental Petroleum | Houston | 1920 |
| Ocean Spray | Lakeville | 1930 |
| Odyssey Marine Exploration | Tampa | 1994 |
| Office Depot | Boca Raton | 1986 |
| Ohio Valley Wrestling | Louisville | 1997 |
| Olin Corporation | Clayton | 1892 |
| Onsemi | Scottsdale | 18 de junho de 1992 |
| Open Invention Network | Durham, Nova Iorque | 10 de novembro de 2005 |
| OpenDNS | São Francisco | julho 2006 |
| OpenTable | São Francisco | 1998 |
| Orbcomm | Fort Lee | 1993 |
| Organon & Co. | Oss | 1923 |
| Orion Pictures | Los Angeles | janeiro 1978 |
| Oshkosh Corporation | Oshkosh | 1917 |
| OTCBB | Washington, D.C. | — |
| Ovation Guitar Company | New Hartford | 1966 |