- Muhlenkamp and Company Inc.
- Multi-Media Holdings, Inc.
- Multigen. Paradigm
- Multistate Associates Incorporated
- Municipal Travel
- Municipio de Barceloneta
- Municipio De Camuy
- Municipio de Ponce
- Municipio de San German
- Municipio de Villalba
- Muniz Engineering Inc.
- Munson Healthcare
- Muray Boys and Girls Club
- Murphy Oil Corporation
- Murray Chamber of Commerce
- Murray City Police Department
- MUSC Health
- MUSC Health Lancaster Medical Center
- Muscogee County Humane Society
- Muscogee County Sheriff
- Muscogee Creek Nation
- Muscogee Manor and Rehabilitation Center.
- Muscular Dystrophy Association
- Muse
- Museum Store Association
- Muskegon Community Health Project
- Muskegon County
- Muskegon County, Michigan
- Muskegon Family Care
- Muskogee Regional Medical Center
- Mustang
- Mutual of Omaha
- My Fit Foods
- My Local Gov
- My Office Business Center
- Mycogen Seeds
- Myers-Cox Co.
- Myron Manufacturing
- Myrtle Beach Area Convention and Visitors Bureau
- Myrtle Beach Convention Center
- Myrtue Medical Center
- Na Pu'uwai
- Nabors Industries Inc.
- NACM
- Nacogdoches County United Way
- NAGNA
- Nailed to the Cross Ministries
- NAM Council of Manufacturing Associations
- Namasco
- Nantahala Orthopaedic Group