| American Megatrends | Norcross | 1985 |
| American Power Conversion | West Kingston | 1981 |
| American Type Founders | Elizabeth | 1892 |
| Ameriprise Financial | Minneapolis | 1894 |
| Amgen | Thousand Oaks | 1980 |
| Amkor Technology | Tempe | 1968 |
| Ampex | Redwood City | 1944 |
| Amphenol | Wallingford Center | 1932 |
| Ancestry.com | Lehi | 1983 |
| Andrew Christian | Hollywood | 2001 |
| Anduril Industries | Califórnia | 2017 |
| Anheuser-Busch | St. Louis | 1852 |
| Aniplex of America | Santa Mônica | 2005 |
| Ansys Inc. | Canonsburg | 1970 |
| Anthropic | São Francisco | 26 de janeiro de 2021 |
| Apollo Computer | Chelmsford | 1980 |
| Apollo Group | Phoenix | 1973 |
| Apple Inc. | Cupertino | 1 de abril de 1976 |
| Applied Materials | Santa Clara | 1967 |
| Aramark | Filadélfia | 1959 |
| ARCO | Los Angeles | 1966 |
| ArenaNet | Bellevue | 2000 |
| Arista Networks | Santa Clara | outubro 2004 |
| Arris Group | Suwanee | 1995 |
| Arthur Andersen | Chicago | 1913 |
| Associação Automobilística Americana | Heathrow | 1902 |
| AST Computers | Irvine | 1980 |
| Auburn Automobile | Auburn | 1900 |
| Augusta National Golf Club | — | 1930 |
| Auntie Anne's | Lancaster U.S. Post Office building | 1988 |
| Autocar Company | Hagerstown | 1897 |
| Automatic Data Processing | Roseland | 1949 |
| AutoNation | Fort Lauderdale | 1996 |
| Avalanche Software | Salt Lake City | 1995 |
| Avid | Burlington | 1987 |
| Avnet | Phoenix | 1921 |
| Axios | condado de Arlington | 2017 |
| Bain Capital | John Hancock Tower | 1984 |
| Baker Motor Vehicle | Cleveland | 1899 |
| Baldwin Locomotive Works | Eddystone | 1825 |
| Baldwin Piano Company | Trumann | 1862 |
| Bank of America | Charlotte | 1784 |
| Bank of America Home Loans | Charlotte | 2009 |
| Bank of America Merrill Lynch | Bank of America Tower | 2009 |
| Bank of North Dakota | Bismarck | 1919 |
| Baskin-Robbins | Canton | 1945 |
| Bausch & Lomb | Vaughan, Rochester | 1853 |
| Bausch Health | Laval, Wilmington | 1960 |