- Treelove
- Tri County Dental Association
- Tri Parish Rehabilitation Hospital
- Tri Star Skyline Medical
- Tri-City Area United Way
- Tri-City Medical Center
- Tri-Cor Industries, Inc.
- Tri-County Care Management, Inc.
- Tri-County Community Health Council
- Tri-County Health Care
- Tri-County Health System, Inc.
- Tri-County Kentucky United Way
- Tri-County Right to Life
- Tri-County United Way
- Tri-State Psychiatric Services
- Tri-Tech Electronics, Inc.
- Triangle Reprographics, Inc.
- Tribridge, Inc.
- Tribune Company
- TRICARE
- Trident
- Trident Health System
- Trident Insurance
- Trident Medical Center
- Trinitas Regional Medical Center
- Trinity Air Medical
- Trinity Baptist Church
- Trinity Health Systems
- Trinity Hospital
- Trinity Lutheran Seminary
- Trinity Medical Center West
- Trinity Mother Frances Hospitals and Clinics
- TRIO Manhattan
- Triple F Inc.
- TriStar Centennial Medical Center
- TriStar Summit Medical Center
- Triumph Technologies, Inc.
- Tropical Financial Credit Union
- Troup County Board of Commissioners
- Troxler Electric Lab
- Troy Community Hospital
- Troy Drury Inn
- Troy Regional Medical Center
- Truckdrivers Union, Local 407
- Truckee Meadows Fire & Rescue
- Truman Medical Centers
- Trump Casino Resorts
- Trus Joist
- Trustee Peabody Retirement Community
- Administradores de Columbia University