- Shrewsbury State Bank
- Shriner's Hospital for Children of Southern California
- Shriners Hospital
- Shriners Hospital for Children - Cincinnati
- Shriners Hospitals for Children
- Shure Inc.
- Sibcy Cline
- Sibley Memorial Hospital
- Sickle Cell Disease Association of America Inc.
- Sidney-Shelby County YMCA
- Siebenthaler Company
- Siemens Building Technologies
- Siemens Corp.
- Siena Heights University
- Siena Village Inc.
- Sierra Community College
- Sierra Consultants
- Sierra Donor Services
- Sierra Medical Center
- Sierra Nevada Memorial Hospital
- Sierra Nevada Tissue Bank
- Sierra Suites, Sierra Vista, AZ
- Sierra View Medical Center
- Sierra Vista Regional Medical Center
- Sierrabay Technology Group
- Sigma Gamma Rho Sorority Inc.
- Signature Association Management
- Signature Events
- Signature Healthcare Brockton Hospital
- Silicon Labs
- Silicon Mountains
- Silicones Environmental Health Safety Council
- Sills Cummis Radin Tischman Epstein andGross
- Siloam Springs Nursing and Rehab
- Siloam Springs Regional Hospital
- Silverado Resort
- Silverado, Annadale
- Silverleaf of Athens, Inc
- Silverliners
- Silvertechnologies
- Simeus Foods International Inc.
- Simmons College
- Simmons Healthcare
- Simmons Manufacturing
- Simply Thick LLC
- Simpson General Hospital
- Sinai Hospital of Baltimore
- Sinai-Grace Hospital
- Sinclair Community College-Phi Theta Kappa
- Singing River Gulfport