- Tri
- Tri City National Bank
- Tri Counties Bank
- Tri Counties Bank - Branch Offices
- Tri County Builders
- Tri County Head Start
- Triad
- Triad Associates
- Triangle Electric
- Triangle Fastener Corporation
- Triangle Real Estate
- Triangle Rent A Car
- Tri-Chem Liquid Embroidery
- Tricor America
- Tricorbraun
- Tricore Reference Laboratories
- Tri-County Electric
- Tri-County Insurance
- Tri-County Insurance Agency
- Tri-County Locksmith
- Tri-County Mental Health Services
- Tri-County Pest Control
- Tri-Dim Filter Corporation
- Trillium
- Trillium Staffing Solutions
- Trimark Physicians Group
- Tri-Mart
- Trimco
- Trimmers
- Trina Turk
- Trinity
- Trinity Auto Sales
- Trinity Broadcasting Network
- Trinity Clinic
- Trinity Consultants
- Trinity Financial Services
- Trinity Health
- Trinity Homes
- Trinity Learning Center