| Ameriprise Financial | Minneapolis | 1894 |
| Amkor Technology | Tempe | 1968 |
| Ampere Computing | Santa Clara | 2017 |
| AMR Corporation | Fort Worth | October 1, 1982 |
| Ancestry.com Inc. | Lehi | 1983 |
| Anheuser-Busch | St. Louis | 1852 |
| Apollo Global Management | Solow Building | 1990 |
| Apollo Group | Phoenix | 1973 |
| Apple Inc. | Cupertino | April 1, 1976 |
| Arby's | Sandy Springs | 1964 |
| ARCO | Los Angeles | 1966 |
| Arctic Cat | Plymouth | June 1960 |
| Arista Networks | Santa Clara | October 2004 |
| Arris Group | Suwanee | 1995 |
| Arrow Electronics | Englewood | 1935 |
| Arthur J. Gallagher & Co. | Itasca | 1927 |
| Ashland Inc. | Covington | 1924 |
| Ashton-Tate | Torrance | August 1980 |
| AT&T | Dallas | October 5, 1983 |
| Atari Corporation | Sunnyvale | July 2, 1984 |
| Au Bon Pain | Boston | 1978 |
| Auburn Automobile | Auburn | 1900 |
| Augusta National Golf Club | — | 1930 |
| Autocar Company | Hagerstown | 1897 |
| Automatic Data Processing | Roseland | 1949 |
| Avatar Press | Rantoul | 1996 |
| Avid Technology | Burlington | 1987 |
| Avnet | Phoenix | 1921 |
| Axios | Arlington County | 2017 |
| Bad Dragon | Phoenix | June 2008 |
| Baltimore and Ohio Railroad | Baltimore | 1827 |
| Bank of America | Charlotte | 1784 |
| Bank of North Dakota | Bismarck | 1919 |
| Bank One Corporation | Chicago | 1863 |
| Barrett Firearms Manufacturing | Christiana | 1982 |
| Baskin-Robbins | Canton | 1945 |
| Bauer Hockey | Exeter | 1927 |
| Bausch Health | Laval, Wilmington | 1960 |
| Be Inc. | Menlo Park | 1990 |
| Beats Electronics | Culver City | 2006 |
| Bell Telephone Company | — | July 9, 1877 |
| Bellator MMA | Newport Beach | 2008 |
| BellSouth | Atlanta | 1984 |
| Ben & Jerry's | South Burlington | 1978 |
| Benchmark | Menlo Park | 1995 |
| Bentley Systems | Exton | 1984 |
| Berkshire Hathaway | Omaha | 1839 |
| Best Buy | Richfield | August 22, 1966 |