| T. B. Radio Communications | Burlington |
| Tai Chi Healthy Bodies Healthy Minds | Milton |
| Talk4Healing, Telephone Helpline and On-line Chat Counselling Services | Thunder Bay |
| Taxi Services - Companies Serving Halton | Halton Region |
| Tech Coaches, Computer Literacy Training Programs | Halton Region |
| TELUS Health MyCare | Toronto Downtown Central |
| Tempus Choral Society | Oakville |
| Tender Soles Footcare, Mobile Nursing Footcare | Burlington |
| Tetra Society of North America, Hamilton/Halton Chapter, Tetra Society Hamilton/Halton Chapter | Hamilton |
| The Halton Resource Connection, Child Care Directory and Information Line | Milton |
| Theatre Burlington | Burlington |
| TheKey, In Home Care Services | Oakville |
| Third Age Learning Burlington | Burlington |
| Thistlecreek Health Care - Home Care Services for Seniors, In-Home Care Services | Oakville |
| Thomas Alton Medical Clinic, Walk-in Medical Clinic | Burlington |
| Thompson Square Medical Centre | Milton |
| Thompson Square Pharmacy | Milton |
| Thompson Walk-In and Medical Clinic | Milton |
| Thrive Counselling, Burlington Head Office | Burlington |
| Thrive Counselling, Walk-in Counselling | Burlington |
| Thrive Counselling, Counselling Services | Burlington |
| Thrive Counselling, Milton Office | Milton |
| Thrive Counselling, North Halton Office | Georgetown |
| Thrive Counselling, Oakville Office | Oakville |
| Thrive Counselling, Partner Assault Response Program | Burlington |
| Thrive Counselling, Violence Against Women Program | Halton Region |
| Top Hat Marching Orchestra | Burlington |
| Toronto Military Family Resource Centre, Personnel Support Programs | Toronto |
| Toronto Public Library, Toronto Reference Library | Toronto |
| Total Care Transport Services | Milton |
| Total Contact Cast for Diabetic Foot Ulcers (The) | Halton Region |
| Total Health Pharmacy, Burlington - Lakeshore Rd, Pharmacy Services | Burlington |
| Total Health Pharmacy, Burlington - Harvester Rd, Pharmacy Services | Burlington |
| Total Health Pharmacy, Milton - Laurier Ave, Pharmacy Services | Milton |
| Total Health Pharmacy, Oakville - Oak Park Blvd, Pharmacy Services | Oakville |
| Total Health Pharmacy, Oakville - Nottinghill Gate, Pharmacy Services | Oakville |
| Total Health Pharmacy, Oakville - Morden Rd, Pharmacy Services | Oakville |
| Total Life Change Health Care, In Home Care Services | Milton |
| Tottering Biped Theatre | Burlington |
| Tourette Canada, Hamilton, Halton and Niagara Region Chapter | Burlington |
| Tourism Burlington, Visitor and Resident Information | Burlington |
| Trafalgar Cardiology | Oakville |
| Trafalgar Pharmacy, Pharmacy Services | Oakville |
| Trafalgar Presbyterian Church | Oakville |
| Trafalgar Senior Homes, Rotary Centennial Towers | Oakville |
| Trafalgar Senior Homes, Woodside Mews | Oakville |
| Trafalgar Township Historical Society | Oakville |
| Trans Canada Trail, National Office | Montréal |
| Trans Lifeline | USA |
| Transforming Faith Worship Centre | Milton |
| Trillium Health Partners, Credit Valley Hospital, Chronic Kidney Disease Program | Mississauga |
| Trillium Health Partners, Credit Valley Hospital, Credit Valley Emergency Department | Mississauga |
| Trillium Health Partners, Credit Valley Hospital | Mississauga |
| Trillium Health Partners, Queensway Health Centre, Centre for Seniors' Medical Psychiatry - Outpatient Program | Etobicoke Central |
| Trillium Health Partners, Queensway Health Centre, Outpatient Physiotherapy Services (Progression) | Etobicoke Central |
| Trillium Health Partners, Queensway Health Centre, Seniors' Health Services - Regional Continence Home Visits Program | Etobicoke Central |
| Trinity Baptist Church | Burlington |
| Trinity United Church, Acton | Acton |
| Trinity United Church, Oakville | Oakville |
| True North Church | Milton |
| True North Imaging, Oakville, Diagnostic imaging services | Oakville |
| TrueCare Medical Centre | Milton |
| TrueCare Medical Pharmacy, Pharmacy Services | Milton |
| Tuesday Night Mens Basketball | Oakville |
| Tyandaga Tennis Club | Burlington |
