| 20th Century Studios Home Entertainment | Century City, Los Angeles | 1976 |
| 23andMe | South San Francisco | abril 2006 |
| 3dfx | São José | 1994 |
| 7-Eleven | Dallas, Irving | 1927 |
| A. T. Cross Company | Lincoln | 1846 |
| A.T. Kearney | Chicago | 1926 |
| AbbVie | North Chicago | 10 de abril de 2012 |
| ABC Family Worldwide | Burbank | 1990 |
| Abercrombie & Fitch | New Albany | 1892 |
| AbioMed | Danvers | 1981 |
| Adient | Dublin | 31 de outubro de 2016 |
| AdMob | Mountain View | 2006 |
| Aeria Games | Berlim | 2006 |
| Agilent Technologies | Santa Clara | 1999 |
| Airtable | São Francisco | 2012 |
| Alcon Entertainment | Los Angeles | 1997 |
| Alexa Internet | São Francisco, Califórnia | abril 1996 |
| Alexion Pharmaceuticals | Cheshire | 1992 |
| Aliança das Indústrias Eletrônicas | condado de Arlington | 1924 |
| Alienware | Miami | 1996 |
| AlliedSignal | Morristown | 1985 |
| Allis-Chalmers | Milwaukee | 1901 |
| Allison Engine Company | Indianápolis | 1915 |
| Ally Financial | Detroit, Nova Iorque | 1919 |
| Altera | São José | 1983 |
| Amblin Television | Universal City | 31 de julho de 1984 |
| AMC Theatres | Kansas City | 1920 |
| AMD | Santa Clara | 1 de maio de 1969 |
| American Axle | Detroit | 1994 |
| American Bridge Company | Coraopolis | 1900 |
| American Cyanamid | Wayne | 1907 |
| American Girl | — | 1986 |
| American International Group | Nova Iorque | 1919 |
| American Locomotive Company | Schenectady, Nova Iorque | 24 de junho de 1901 |
| American Power Conversion | West Kingston | 1981 |
| American Tower Corporation | Boston | 1995 |
| American Type Founders | Elizabeth | 1892 |
| Amlogic | Santa Clara | 1995 |
| Ampere Com | Santa Clara | 2017 |
| Ampex | Redwood City | 1944 |
| Amphenol | Wallingford Center | 1932 |
| AMR Corporation | Fort Worth | 1 de outubro de 1982 |
| Ancestry.com | Lehi | 1983 |
| Anheuser-Busch | St. Louis | 1852 |
| Ansys Inc. | Canonsburg | 1970 |
| Apollo Computer | Chelmsford | 1980 |
| Apollo Group | Phoenix | 1973 |
| Aramark | Filadélfia | 1959 |