- 20th Century Insurance Companies/Industries & Subsidaries
- 3Com Corporation
- 3M Corporation - Volunteer Program
- A & E Television Networks
- A.O. Smith
- AAA Laser Service & Supplies
- AAL Aid Association for Lutherans
- AARP
- Abbott Laboratories
- ABC/Capital Cities
- Abell Foundation, Inc.
- Abell-Hanger Foundation
- Abemarle Corporation
- Abercrombie & Kent
- Abernathy/MacGregor Group
- Aboda, Inc.
- Access Group
- Access Sciences Corporation
- ACCO Brands, Inc.
- ACCO USA Inc.