Politics and Business magazines
- Marvin Lumber & Cedar Company
- Mary Kay, Inc.
- Maryland & Virginia Milk Producers Cooperative Association, Inc.
- Mashantucket Pequot Gaming Enterprise Inc.
- Masland Corporation
- Masonite International Corporation
- Massey Energy Company
- Master Lock Company
- MasterBrand Cabinets, Inc.
- MasterCard International, Inc.
- MasterCraft Boat Company, Inc.
- Matalan PLC
- Match.com, LP
- Material Sciences Corporation
- Materials
- Matra-Hachette S.A.
- Matria Healthcare, Inc.
- Matrix Essentials Inc.
- Matrix Service Company
- Matrixx Initiatives, Inc.