- A. and J. Kraut1
- A., Tony1
- A.B. Felgemaker Organ Co1
- A.B.C. Construction Corp.1
- A.B.C. Homes, Inc.3
- A.B.G. Construction Corp.1
- A.C. Management Corp.1
- A.D.A.M., Inc.19
- A.F. Development Co., Inc.1
- A.H. Andrews & Co.1
- A.H. Montague & Son2
- A.H. and L. Building Corp.2
- A.L. Bancroft & Company1
- A.L. Lyon Co.1
- A.M. Bing and Son Realty Corp.4
- A.P.S. Realty Corp.1
- A.S. Barnes & Co.3
- A.T. Demarest & Co.1
- A.Y. McDonald & Morrison Mfg. Co.1
- ABC News12
- ABC Television Network9
- ABC Video Enterprises3
- AFL-CIO1
- AFL-CIO. Committee on Political Education1
- AMIH Housing Services, Inc.1
- ATV Network (Firm)1
- AVM television1
- Aalto, Alvar, 1898-19761
- Aaron A. Colter & Co.1
- Aaron Green Co.13
- Aaronson and Heidrich3
- Abarca de Bolea, Pedro Pablo, conde de Aranda, 1719-179812
- Abbenseth, William, 1898-19721
- Abbey, George, 1932-1
- Abbinanti, Frank1
- Abbot and Cohen (Musical group)1
- Abbot, Michael1
- Abbott Hotels1
- Abbott and Adams, Inc.3
- Abbott and Costello (Comedy team)1
- Abbott, Edith, 1876-19571
- Abbott, George, 1887-19951
- Abbott, Jacob, 1803-18791
- Abbott, Karl P.2
- Abdallah, Mogniss Hamed1
- Abdel Kader, Ali1
- Abdul, Raoul1
- Abdurahman, Khadijah4
- Abe Saul Construction Corp.1
- Abe, Harry1
- Abel Bros. & Co.2
- Abel, Elie1
- Abel, Lionel1
- Abel, Smith & Co.1
- Abel, Walter Charles, 1898-1
- Abell, Erica2
- Abell, Jane, 1928-20191
- Abell, Nan Taylor1
- Abeloff, Abram J. (Abram Joseph), 1900-19971
- Aberbach, Joachim Jean4