- Outsourcing Solutions, Inc.
- Ovation Research Group
- Overhead Door
- Overland Park Convention and Visitors Bureau
- Overland Park Regional Medical Center
- Overlook Medical Center
- Overnite Transportation Company
- Oviedo Medical Center
- Owen High School
- Owen Middle School
- Owens and Minor, Inc.
- Owens Community College
- Owens Corning
- Owensboro Health Regional Hospital
- Oxford Development Company
- Oxford Health Plans
- Ozanam Hall of Queens Nursing Home
- Ozark Foothills Regional Planning Commission
- Ozark Health
- P.R. Advertising Specialties Association
- P.R.O.C.E.E.D.
- PA American Water Company, Pittsburgh Operations
- PA Capital Regions Vacation Bureau
- Pace University
- Pacific Biometrics, Inc.
- Pacific Bridge, Inc.
- Pacific Coast Building Products
- Pacific Data Designs, Inc
- Pacific Gas and Electic
- Pacific Gas and Electronics
- Pacific Health Alliance
- Pacific Islander Community Council
- Pacific Life Insurance
- Pacific Northwest Transplant Bank
- Pacific Retirement Services Inc.
- Pacifica Hospital of the Valley
- Pack 779 - Webelos - 1
- PACO
- Padded Room LLC
- Paducah Drury Inn
- Paducah Drury Suites
- Paducah Pear Tree Inn
- Paducah-McCracken County CVB
- PaeTec Communications, Inc.
- Pagan Atlanta
- Page Memorial Hospital
- Paideia Academies
- Paideia Academy
- PaineWebber Inc.
- Painter Russell and Associates, PLLL