| 23andMe | South San Francisco | abril 2006 |
| 3Com | Marlborough | 1979 |
| 3dfx | San José | 1994 |
| 7-Eleven | Dallas, Irving | 1927 |
| ABKCO Records | Nueva York | 1961 |
| About.me | — | 2010 |
| Access Industries | Nueva York | 1986 |
| Ace Hardware | Oak Brook | 1924 |
| ACNielsen | Chicago | 1923 |
| Activision Blizzard | Santa Mónica | 10 de julio de 2008 |
| Acxiom | Wilmington, Conway | 2018 |
| AddThis | Vienna | 2006 |
| Advent International | Boston | 1984 |
| AeroVironment | Simi Valley | 1971 |
| Aetna | Hartford | 1853 |
| Affirm Films | Culver City | 2008 |
| Aflac | Columbus | 1955 |
| AGEIA | Santa Clara | 2002 |
| Agencia Nacional de Detectives Pinkerton | Ann Arbor | febrero 1855 |
| Agua Fiji | Los Ángeles | 1996 |
| Air Products & Chemicals | Detroit | 1940 |
| Airbnb | San Francisco | 2008 |
| Aksys Games | Torrance | 14 de julio de 2006 |
| Alamo Rent a Car | Clayton | 1974 |
| Alco | Schenectady, Nueva York | 24 de junio de 1901 |
| Alcoa | Nueva York | 1907 |
| Aldus Corporation | Seattle | 1 de febrero de 1984 |
| Alesis | Cumberland | 1980 |
| Alienware | Miami | 1996 |
| AllianceBernstein | Nashville | 1967 |
| AlliedSignal | Morristown | 1985 |
| Allstate | Northbrook | 17 de abril de 1931 |
| Alltel | Little Rock | 1943 |
| Altair Engineering | Troy | 1985 |
| Altera | San José | 1983 |
| Amaze Entertainment | Kirkland | 1997 |
| AMD | Santa Clara | 1 de mayo de 1969 |
| American Axle | Detroit | 1994 |
| American Bridge Company | Coraopolis | 1900 |
| American Eagle Outfitters | Pittsburgh | 1977 |
| American Express | Nueva York | 1850 |
| American International Group | Nueva York | 1919 |
| American Megatrends | Norcross | 1985 |
| American Power Conversion | West Kingston | 1981 |
| American Society of Composers, Authors and Publishers | Estados Unidos, Nueva York | 1914 |
| American Tobacco Company | Durham | 31 de enero de 1890 |
| American Tourister | Rhode Island | 1933 |
| American Type Founders | Elizabeth | 1892 |