| 20th Century Studios Home Entertainment | Century City, Los Angeles | 1976 |
| 3Com | Marlborough | 1979 |
| 3M | Maplewood | 1902 |
| A.T. Kearney | Chicago | 1926 |
| AbbVie | North Chicago | 10 de abril de 2012 |
| ACNielsen | Chicago | 1923 |
| Activision Blizzard | Santa Mônica | 10 de julho de 2008 |
| AddThis | Vienna | 2006 |
| Adient | Dublin | 31 de outubro de 2016 |
| Adobe | São José | 28 de fevereiro de 1982 |
| Aeria Games | Berlim | 2006 |
| Aero Commander | Culver City | 1944 |
| Aerojet Rocketdyne | Palm Bay | junho 2013 |
| AeroVironment | Simi Valley | 1971 |
| Aetna | Hartford | 1853 |
| Affliction Entertainment | Los Angeles | 2008 |
| Agilent Technologies | Santa Clara | 1999 |
| Airtable | São Francisco | 2012 |
| Akamai Technologies | Cambridge, Massachusetts | 1998 |
| Alamo Rent a Car | Clayton | 1974 |
| Albertsons | Boise | 1939 |
| Alcoa | Nova Iorque | 1907 |
| Alcon Entertainment | Los Angeles | 1997 |
| Alesis | Cumberland | 1980 |
| Alexion Pharmaceuticals | Cheshire | 1992 |
| Alfred Music Publishing | Los Angeles | 1922 |
| Aliança das Indústrias Eletrônicas | condado de Arlington | 1924 |
| Alienware | Miami | 1996 |
| Allen-Bradley | Milwaukee | 1903 |
| AllianceBernstein | Nashville | 1967 |
| AlliedSignal | Morristown | 1985 |
| Allison Engine Company | Indianápolis | 1915 |
| Allison Transmission | Indianápolis | 1916 |
| Ally Financial | Detroit, Nova Iorque | 1919 |
| Altair Engineering | Troy | 1985 |
| Altera | São José | 1983 |
| Amazon | Seattle | 5 de julho de 1994 |
| AMC Theatres | Kansas City | 1920 |
| AMD | Santa Clara | 1 de maio de 1969 |
| American Bantam | Butler | 1935 |
| American Cyanamid | Wayne | 1907 |
| American Express | Nova Iorque | 1850 |
| American Girl | — | 1986 |
| American Locomotive Company | Schenectady, Nova Iorque | 24 de junho de 1901 |
| American Power Conversion | West Kingston | 1981 |
| American Tourister | Rhode Island | 1933 |
| American Type Founders | Elizabeth | 1892 |
| American Wrestling Association | Minneapolis | 1960 |