| Maxwell Technologies | San Diego | 1965 |
| Maybelline | New York City | 1915 |
| McCormick & Company | Hunt Valley | 1669 |
| McDonald's | Chicago | May 15, 1940 |
| Memorex | Cerritos | 1961 |
| Mercury Marine | Fond du Lac | 1939 |
| Meredith Corporation | Des Moines | 1902 |
| Merrill | New York City | January 6, 1914 |
| Meta Platforms | Menlo Park | July 29, 2004 |
| MGM Television | Beverly Hills | 1956 |
| Micro Instrumentation and Telemetry Systems | Albuquerque | 1970 |
| Micron Technology | Boise | October 1978 |
| Middle-earth Enterprises | Berkeley | 2022 |
| Missouri Pacific Railroad | St. Louis | 1917 |
| Mistwalker | Tokyo, Japan, Honolulu | 2004 |
| MITRE Corporation | Bedford | 1958 |
| Moderna | Cambridge | 2010 |
| Molex | Lisle | 1938 |
| Mondo Media | San Francisco | 1988 |
| Monster Beverage | Minnesota | 1935 |
| Moody's Investors Service | 7 World Trade Center | 1909 |
| MoPar | Chrysler Headquarters and Technology Center | 1933 |
| MOS Technology | Norristown | 1969 |
| Motorola Solutions | Chicago | January 4, 2011 |
| MSA Safety | Pittsburgh, Cranberry Township | 1914 |
| México. | Rome, San Clemente | 1999 |
| Narus | Sunnyvale | 1997 |
| National Instruments | Austin | 1976 |
| National Oilwell Varco | Houston | 1862 |
| Neiman Marcus | Dallas | 1907 |
| Neon | New York | 2017 |
| NetApp | Sunnyvale | 1992 |
| Netflix, Inc. | Los Gatos | August 29, 1997 |
| NetJets | Columbus | 1964 |
| Neuberger Berman | New York City | 1939 |
| New Balance | Boston | 1906 |
| New Holland | Italy | 1891 |
| New York Central Railroad | Helmsley Building | December 23, 1914 |
| New York Shipbuilding Corporation | Camden | 1899 |
| Newegg | City of Industry | 2001 |
| Nexstar Media Group | Irving | June 17, 1996 |
| NeXT | Palo Alto, Redwood City | June 20, 1985 |
| Nielsen Company | New York City | 1994 |
| NIQ | Chicago | 1923 |
| Nomura Securities Co Ltd | Nihonbashi, Tokyo | May 7, 2001 |
| Norfolk Southern Railway | Norfolk | 1894 |
| Northern Pacific Railway | Saint Paul | July 2, 1864 |
| Northern Trust | Illinois, Chicago | 1889 |