- South Miami Hospital
- South Mississippi County Regional Medical Center
- South Nassau Communities Hospital
- South Natomas Transportation Management Association
- South Ogden Police Department
- South Padre Island Texas Convention and Visitors Bureau
- South Seas Resort, Captiva
- South Seminole Hospital
- South Shore Hospital
- South Shore Hospital
- South Texas Blood and Tissue Center
- South Texas ENT Consultants
- South Texas Health System
- South Texas Spinal Clinic
- South Texas Veterans Health Care System, Audie Murphy Division
- South Towne Center
- South Towne Senior Residence
- South Traic Fire and Rescue
- South Valley Auto Plaza
- South Winds, Inc.
- Southampton Memorial Hospital
- Southcoast Hospital Group
- Southeast Asian Community Center - San Francisco
- Southeast Asian Mutual Assistance Association Coalition
- Southeast Georgia Health System
- Southeast Georgia Health System - Brunswick Campus
- Southeast Georgia Health System - Camden Campus
- Southeast Health
- Southeast Industrial Equipment Inc.
- Southeast Iowa Regional Medical Center - Fort Madison
- Southeast Iowa Regional Medical Center - West Burlington
- Southeast Louisiana Area Health Education Center
- Southeast Louisiana Veterans Health Care System
- Southeast Rehab
- Southeastern Container, Inc.
- Southeastern Institute of Research, Inc.
- Southeastern Kidney Council- ESRA Network 6
- Southeastern Ohio Regional Medical Center
- Southeastern Regional Medical Center
- Southern Arizona VA Health Care System
- Southern Avionics Company
- Southern Building Systems, Inc.
- Southern California Hospital at Culver City
- Southern California Hospital at Hollywood
- Southern Company
- Southern Concrete Materials, Inc.
- Southern Connecticut State University
- Southern Eye Bank
- Southern Financial Bank - Horsepen Branch
- Southern Governors' Association